1
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Ghorbanizamani F, Moulahoum H, Timur S. Ionic liquid-reinforced Hydroxyapatite@nano-TiO 2 as a green platform for Immuno-electrochemical sensing applications. Talanta 2024; 280:126688. [PMID: 39128315 DOI: 10.1016/j.talanta.2024.126688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 08/02/2024] [Accepted: 08/06/2024] [Indexed: 08/13/2024]
Abstract
In contemporary society, developing dependable point-of-care (POC) biosensors for the timely detection of cancer markers is crucial. Among various sensor types, screen-printed electrode (SPE)-based sensors, particularly electrochemical ones, stand out as promising candidates for POC applications. Despite ongoing efforts to create numerous SPE-based sensors, there is a continuous pursuit to enhance their sensitivity and analytical capabilities. This study presents an advanced electrochemical sensor designed to sensitively detect the hepatocellular carcinoma (HCC) marker Alpha-fetoprotein (AFP) in saliva. The sensor employs a gold SPE modified with hydroxyapatite, TiO2 nanoparticles, 1-butyl-3-methylimidazolium bis(trifluoromethyl sulfonyl)imide ionic liquid (IL), and AFP monoclonal antibodies. After thorough characterization and optimization using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), the biosensor exhibited a broad detection range (0.01-400 ng/mL), a low limit of detection (LOD) at 0.058 ng/mL, and demonstrated high selectivity, repeatability, reproducibility, and stability. Furthermore, when tested with spiked human saliva samples, the biosensor displayed excellent recovery and robustness, showcasing its potential for noninvasive and POC diagnosis of HCC. In an environmentally conscious evaluation, the biosensor's greenness was assessed using the AGREE metric, yielding a high score of 0.85. This score indicates the biosensor's alignment with the principles of green analytical chemistry, underlining its eco-friendly attributes. This innovative electrochemical sensor contributes to the ongoing efforts for efficient and reliable POC diagnostic tools and aligns with a broader commitment to developing environmentally friendly solutions.
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Affiliation(s)
- Faezeh Ghorbanizamani
- Biochemistry Department, Faculty of Science, Ege University, 35100, Bornova, Izmir, Turkey
| | - Hichem Moulahoum
- Biochemistry Department, Faculty of Science, Ege University, 35100, Bornova, Izmir, Turkey.
| | - Suna Timur
- Biochemistry Department, Faculty of Science, Ege University, 35100, Bornova, Izmir, Turkey; Central Research Testing and Analysis Laboratory Research and Application Center, Ege University, 35100, Bornova, Izmir, Turkey.
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2
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Velmurugan G, Ganapathi Raman R, Sivaprakash P, Viji A, Cho SH, Kim I. Functionalization of Fluorine on the Surface of SnO 2-Mg Nanocomposite as an Efficient Photocatalyst for Toxic Dye Degradation. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2494. [PMID: 37687002 PMCID: PMC10489931 DOI: 10.3390/nano13172494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 08/16/2023] [Accepted: 08/17/2023] [Indexed: 09/10/2023]
Abstract
This work reports on the photocatalytic activity of tin oxide (SnO2)-doped magnesium (Mg) and fluorine (F) nanoparticles for methyl orange and safranin dye degradation under sunlight irradiation. Nanocatalysis-induced dye degradation was examined using UV-visible spectroscopy and a pseudo-first-order kinetics model. The results indicate that the prepared nanoparticles exhibit superior photocatalytic activity, and the degradation of methyl orange (MO) dye is approximately 82%. In contrast, the degradation of safranin dye is 96% in the same time interval of 105 min. The calculated crystallite size of the SnO2-Mg-F nanocomposite is 29.5 nm, which respects the particle size found in the DLS analysis with a tetragonal structure and spherical morphology affirmed. The optical characteristics were assessed, and their respective bandgap energies were determined to be 3.6 eV. The influence of F in Mg and SnO2 is recognized with the XRD and FT-IR spectra of the prepared particles.
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Affiliation(s)
- G. Velmurugan
- Department of Physics, Noorul Islam Centre for Higher Education, Kumaracoil, Kanyakumari 629180, Tamil Nadu, India;
| | - R. Ganapathi Raman
- Department of Physics, Saveetha Engineering College (Autonomous), Chennai 602105, Tamil Nadu, India
| | - P. Sivaprakash
- Department of Mechanical Engineering, Keimyung University, Daegu 42601, Republic of Korea;
| | - A. Viji
- Department of Physics, Kongunadu College of Engineering and Technology, Thottiyam 621215, Tamil Nadu, India;
| | - Shin Hum Cho
- Department of Chemical Engineering, Keimyung University, Daegu 42601, Republic of Korea;
| | - Ikhyun Kim
- Department of Mechanical Engineering, Keimyung University, Daegu 42601, Republic of Korea;
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3
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The Effect of Cu(II) Nanoparticle Decoration on the Electron Relaxations and Gaseous Photocatalytic Oxidations of Nanocrystalline TiO2. Catalysts 2023. [DOI: 10.3390/catal13030550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
Abstract
A photocatalytic effect arises from the electron relaxation of semiconductors. Directing the electron relaxation toward photocatalytic reactions is the focus of photocatalytic studies. Co-catalyst decoration is a main way to modulate the electron relaxation, and the Cu(II) nanoparticles have been widely studied as an important co-catalyst. However, the detailed mechanism is still not well known. The current study is devoted to investigating the effect of the Cu(II) nanoparticle decoration on the electron relaxations for TiO2 through in situ photochromism and photoconductances, based on which the relation to the photocatalytic properties was discussed. The result shows that the Cu(II)/Cu(0) redox couple assists the double electron transfer from TiO2 to O2, while the Cu(I)/Cu(0) redox couple assists the single electron transfer to O2. Although the Cu(II) decoration changes the mechanism and increases the rate of the electron relaxations, the electron relaxation does not occur via the Cu redox couple assistance. It was found that the electron relaxation kinetics depends on the reduced Cu species, which can be greatly increased when the Cu(II) was reduced to Cu(0). It is also revealed that the electron relaxation corresponds to the electron transfer from TiO2 to O2, but it does not occur through the Cu redox couple assistance. The result also shows that the increase in the electron relaxation is mainly directed toward the recombination rather than photocatalytic reactions. The present research gains some insights on the role of the co-catalysts in the electron relaxations and its relation to photocatalysis; this should be meaningful for designing novel photocatalytic materials.
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4
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Svensson F, Österlund L. One‐step synthesis of sulfate‐modified titania nanoparticles with surface acidic and sustained photocatalytic properties via solid‐state thermolysis of titanyl sulfate. ChemCatChem 2022. [DOI: 10.1002/cctc.202200682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fredric Svensson
- Uppsala Universitet Teknisk-naturvetenskapliga vetenskapsomradet: Uppsala Universitet Teknisk-naturvetenskapliga fakulteten Deptarment of Materials Science and Engineering Läggerhyddsvägen 1 75103 Uppsala SWEDEN
| | - Lars Österlund
- Uppsala University: Uppsala Universitet Department of Materials Science and Engineering P.O. Box 35Lägerhyddsvägen 1 75103 Uppsala SWEDEN
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5
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Xie L, Lu J, Ye G, Yao J, Zou X, Zhu C. Decomposition of gaseous chlorobenzene using a DBD combined CuO/ α-Fe 2O 3 catalysis system. ENVIRONMENTAL TECHNOLOGY 2022; 43:2743-2754. [PMID: 33657965 DOI: 10.1080/09593330.2021.1899292] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
Copper oxide and hematite (CuO/α-Fe2O3) composite catalysts were prepared by using goethite as precursor adopted impregnation way and applied to the dielectric barrier discharge (DBD) catalytic decomposition of gaseous chlorobenzene. The CuO/α-Fe2O3 composite was characterised by X-ray diffraction, Brunauer-Emmett-Teller method, scanning electron microscopy and X-ray photoelectron spectrometer technique. The decomposition efficiency and energy yield of gaseous chlorobenzene in DBD catalysis system were studied by a function of gas flow rate, initial concentration and input voltage. The results showed that the CuO/α-Fe2O3 composite catalyst exhibited remarkable performance on chlorobenzene decomposition when the molar ratio was 0.4 and calcination temperature was 450°C. When the chlorobenzene initial concentration was 230 mg m-3, the chlorobenzene decomposition efficiency and mineralisation rate on the DBD catalysis system reached 73.33% and 63.37%, respectively, its decomposition and mineralisation efficiency were enhanced about 20.5% and 16.61%, respectively, compared with the bare DBD system, and it also benefited to significantly reduce the ozone and NO2 by-products. The possible pathway of chlorobenzene decomposition in the DBD catalytic hybrid system was proposed based on the products analysis.
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Affiliation(s)
- Linxuan Xie
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, People's Republic of China
| | - Jun Lu
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, People's Republic of China
- Center of Analysis & Measurement, Hefei University of Technology, Hefei, People's Republic of China
| | - Ganggui Ye
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, People's Republic of China
| | - Jieyu Yao
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, People's Republic of China
| | - Xuehua Zou
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, People's Republic of China
| | - Chengzhu Zhu
- School of Resource and Environmental Engineering, Hefei University of Technology, Hefei, People's Republic of China
- Institute of Atmospheric Environment & Pollution Control, Hefei University of Technology, Hefei, People's Republic of China
- Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, Hefei University of Technology, Hefei, People's Republic of China
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6
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Zheng Y, Su Y, Pang C, Yang L, Song C, Ji N, Ma D, Lu X, Han R, Liu Q. Interface-Enhanced Oxygen Vacancies of CoCuO x Catalysts In Situ Grown on Monolithic Cu Foam for VOC Catalytic Oxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1905-1916. [PMID: 34856794 DOI: 10.1021/acs.est.1c05855] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The development of highly efficient and stable monolithic catalysts is essential for the removal of volatile organic compounds (VOCs). Copper foam (CF) is a potential ideal carrier for monolithic catalysts, but its low surface area is not conducive to dispersion of active species, thus reducing the interface interaction with active species. Herein, a vertically oriented Cu(OH)2 nanorod was in situ grown on the CF, which acted as the template and precursor to synthesize CoCu-MOF. The optimized catalyst (12CoCu-R) delivers excellent performance for acetone oxidation with a T90 of 195 °C. Impressively, the catalyst demonstrated satisfactory stability in long-term, cycle, water resistance, and high airspeed tests. Therefore, the present study provides a novel strategy for rationally designing efficient monolithic catalysts for VOC oxidation and other environmental applications.
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Affiliation(s)
- Yanfei Zheng
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Yun Su
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Caihong Pang
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Lizhe Yang
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Chunfeng Song
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
| | - Na Ji
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Degang Ma
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Xuebin Lu
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Rui Han
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
| | - Qingling Liu
- Tianjin Key Lab of Indoor Air Environmental Quality Control, School of Environmental Science and Technology, Tianjin University, Tianjin 300350, China
- State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
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7
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Liu B, Wang J, Parkin IP, Zhao X. The effect of Cu dopants on electron transfer to O 2 and the connection with acetone photocatalytic oxidations over nano-TiO 2. Phys Chem Chem Phys 2021; 23:8300-8308. [PMID: 33875994 DOI: 10.1039/d1cp00118c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Modifying TiO2 with the Cu element has been shown to be useful for photocatalysis. Although it had been known that Cu species could trap electrons from TiO2, whether they can affect the kinetics of electron transfer and how this can contribute to photocatalysis still remain unknown. In the current research, Cu-TiO2 samples were firstly prepared with a hydrothermal reaction and characterized in detail. It was shown that Cu elements were doped in the TiO2 lattice in +1/0 valence states and have a minor effect on the TiO2 structure. By means of photoconductances, it is shown that the Cu dopants could catalyze the electron transfer from TiO2 to O2 by reducing the apparent activation energy (Eapp) by about 2 times. The photocatalytic experiments conducted at different temperatures showed that the Eapp of the acetone photocatalytic oxidations could be decreased by ∼2 times; this implies that the Cu dopants change the photocatalytic pathway. First-principles computation showed that the surface Cu dopants, along with the compensated oxygen vacancies, can mediate both of the electron and hole transfer. By combining other studies, we proposed that the Cu sites could act as Lewis acid and base pairs that could combine with acetone and O2 molecules under UV light illumination; this allows electron transfer to O2via the Cu sites that then react with acetone. As compared to pure TiO2 surfaces, the different chemical environment of the Cu sites leads to the decrease in the Eapp of photocatalysis.
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Affiliation(s)
- Baoshun Liu
- State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan City, Hubei province 430070, P. R. China.
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8
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Lin F, Wang H, Zhao Y, Fu J, Mei D, Jaegers NR, Gao F, Wang Y. Elucidation of Active Sites in Aldol Condensation of Acetone over Single-Facet Dominant Anatase TiO 2 (101) and (001) Catalysts. JACS AU 2021; 1:41-52. [PMID: 34467270 PMCID: PMC8395664 DOI: 10.1021/jacsau.0c00028] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Indexed: 06/13/2023]
Abstract
Aldol condensations of carbonyl compounds for C-C bond formation are a very important class of reactions in organic synthesis and upgrading of biomass-derived feedstocks. However, the atomic level understanding of reaction mechanisms and structure-activity correlation on widely used transition metal oxide catalysts are limited due to the high degree of structural heterogeneity of catalysts such as commercial TiO2 powders. Here, we provide a deep understanding of the reaction mechanisms, kinetics, and structure-function relationships for vapor phase acetone aldol condensation through the controlled synthesis of two catalysts with high surface areas and clean, dominant facets, coupled with detailed characterization and kinetic studies that are further assisted by density functional theory (DFT) calculations. Temperature-dependent diffuse reflectance infrared Fourier transform spectroscopy showed the existence of abundant acetone bonded to surface hydroxyl groups (acetone-OsH) and acetone bonded to Lewis acid sites (acetone-Ti5c) on the surface of both {101} and {001} facet dominant TiO2. Intermolecular C-C coupling of theenolate intermediate from acetone-Ti5c and a vicinal acetone-OsH is a kinetically relevant step, which is consistent with kinetic and isotopic studies as well as DFT calculations. The {001} facet showed a lower apparent activation energy (or higher activity) than the {101} facet. This is likely caused by the weaker Lewis acid and Brønsted base strengths of the {001} facet which favors the reprotonation-desorption of the coupled intermediate, making the C-C coupling step more exothermic on the {001} facet and resulting in an earlier transition state with a lower activation barrier. It is also possible that the {001} facet has a smoother surface configuration and less steric hindrance during intermolecular C-C bond formation than the {101} facet.
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Affiliation(s)
- Fan Lin
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99354, United States
| | - Huamin Wang
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99354, United States
| | - Yuntao Zhao
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99354, United States
| | - Jia Fu
- School
of Chemistry and Chemical Engineering, Tiangong
University, Tianjin 300387, China
| | - Donghai Mei
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99354, United States
- School
of Chemistry and Chemical Engineering, Tiangong
University, Tianjin 300387, China
| | - Nicholas R. Jaegers
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99354, United States
- The
Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States
| | - Feng Gao
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99354, United States
| | - Yong Wang
- Institute
for Integrated Catalysis, Pacific Northwest
National Laboratory, Richland, Washington 99354, United States
- The
Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States
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9
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Wu S, Ishisone K, Sheng Y, Manuputty MY, Kraft M, Xu R. TiO 2 with controllable oxygen vacancies for efficient isopropanol degradation: photoactivity and reaction mechanism. Catal Sci Technol 2021. [DOI: 10.1039/d1cy00417d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Flame-synthesized TiO2−x with controllable defects exhibits a remarkable photooxidation efficiency of gaseous isopropanol with the reaction mechanism investigated.
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Affiliation(s)
- Shuyang Wu
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- Singapore 637459
- Singapore
- C4T CREATE
| | - Kana Ishisone
- Department of Materials Science and Engineering
- Graduate School of Materials and Chemical Technology
- Tokyo Institute of Technology
- Tokyo
- Japan
| | - Yuan Sheng
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- Singapore 637459
- Singapore
- C4T CREATE
| | - Manoel Y. Manuputty
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- Singapore 637459
- Singapore
- C4T CREATE
| | - Markus Kraft
- C4T CREATE
- National Research Foundation
- Singapore 138602
- Singapore
- Department of Chemical Engineering and Biotechnology
| | - Rong Xu
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- Singapore 637459
- Singapore
- C4T CREATE
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10
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Qian X, Yang W, Gao S, Xiao J, Basu S, Yoshimura A, Shi Y, Meunier V, Li Q. Highly Selective, Defect-Induced Photocatalytic CO 2 Reduction to Acetaldehyde by the Nb-Doped TiO 2 Nanotube Array under Simulated Solar Illumination. ACS APPLIED MATERIALS & INTERFACES 2020; 12:55982-55993. [PMID: 33283493 DOI: 10.1021/acsami.0c17174] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The adsorption and activation of CO2 molecules on the surface of photocatalysts are critical steps to realize efficient solar energy-induced CO2 conversion to valuable chemicals. In this work, a defect engineering approach of a high-valence cation Nb-doping into TiO2 was developed, which effectively enhanced the adsorption and activation of CO2 molecules on the Nb-doped TiO2 surface. A highly ordered Nb-doped TiO2 nanotube array was prepared by anodization of the Ti-Nb alloy foil and subsequent annealing at 550 °C in air for 2 h for its crystallization. Our sample showed a superior photocatalytic CO2 reduction performance under simulated solar illumination. The main CO2 reduction product was a higher-energy compound of acetaldehyde, which could be easily transported and stored and used to produce various key chemicals as intermediates. The acetaldehyde production rate was over ∼500 μmol·g-1·h-1 with good stability for repeated long-time uses, and it also demonstrated a superior product selectivity to acetaldehyde of over 99%. Our work reveals that the Nb-doped TiO2 nanotube array could be a promising candidate with high efficiency and good product selectivity for the photocatalytic CO2 reduction with solar energy.
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Affiliation(s)
- Xinzhu Qian
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, P. R. China
| | - Weiyi Yang
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, P. R. China
| | - Shuang Gao
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, P. R. China
| | - Jun Xiao
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
| | - Swastik Basu
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Anthony Yoshimura
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Yunfeng Shi
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Vincent Meunier
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Qi Li
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, P. R. China
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11
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Photocatalytic Oxidation of Propane Using Hydrothermally Prepared Anatase-Brookite-Rutile TiO 2 Samples. An In Situ DRIFTS Study. NANOMATERIALS 2020; 10:nano10071314. [PMID: 32635452 PMCID: PMC7407931 DOI: 10.3390/nano10071314] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 06/20/2020] [Accepted: 07/01/2020] [Indexed: 12/01/2022]
Abstract
Photocatalytic oxidation of propane using hydrothermally synthesized TiO2 samples with similar primary crystal size containing different ratios of anatase, brookite and rutile phases has been studied by measuring light-induced propane conversion and in situ DRIFTS (diffuse reflectance Fourier transform infrared spectroscopy). Propane was found to adsorb on the photocatalysts, both in the absence and presence of light. The extent of adsorption depends on the phase composition of synthesized titania powders and, in general, it decreases with increasing rutile and brookite content. Still, the intrinsic activity for photocatalytic decomposition of propane is higher for photocatalysts with lower ability for propane adsorption, suggesting this is not the rate-limiting step. In situ DRIFTS analysis shows that bands related to adsorbed acetone, formate and bicarbonate species appear on the surface of the photocatalysts during illumination. Correlation of propane conversion and infrared (IR) data shows that the presence of formate and bicarbonate species, in excess with respect to acetone, is composition dependent, and results in relatively low activity of the respective TiO2. This study highlights the need for precise control of the phase composition to optimize rates in the photocatalytic oxidation of propane and a high rutile content seems to be favorable.
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12
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Wang Z, Yang H, Liu R, Xie S, Liu Y, Dai H, Huang H, Deng J. Probing toluene catalytic removal mechanism over supported Pt nano- and single-atom-catalyst. JOURNAL OF HAZARDOUS MATERIALS 2020; 392:122258. [PMID: 32092645 DOI: 10.1016/j.jhazmat.2020.122258] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 06/10/2023]
Abstract
Commercial TiO2 supported 0.20 wt% Pt catalyst is obtained via the molten salt method, and both Pt nanoparticles and single atom Pt sites are observed. It exhibits high catalytic performance for toluene oxidation, with T50 and T90 being 173 and 183 °C, respectively. Reaction intermediates including benzene, p-xylene, o-xylene, benzaldehyde, phthalic acid, maleic anhydride, itaconic anhydride, acetone, and acetic acid, are detected during toluene oxidation. On this basis, likely toluene combustion reaction pathway is provided. Benzaldehyde is the most stable surface intermediate, and its oxidation can be rate-limiting for the entire toluene oxidation reaction. 2-10.0 vol% H2O slightly inhibits the reaction by competing surface sites with the reactant, while it does not poison the catalyst. 2.5-10.0 vol% CO2 slightly poisons the catalyst by surface carbonate formation, whereas 50 ppm SO2 severely poisons the catalyst by sulfite/sulfate formation.
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Affiliation(s)
- Zhiwei Wang
- Key Laboratory of Beijing on Regional Air Pollution Control, Beijing Key Laboratory for Green Catalysis and Separation, and College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China
| | - Huanggen Yang
- Guangxi Key Laboratory of Agricultural Resources Chemistry and Biotechnology, College of Chemistry and Food Science, Yulin Normal University, Yulin, 537000, Guangxi, China
| | - Rui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Shaohua Xie
- Key Laboratory of Beijing on Regional Air Pollution Control, Beijing Key Laboratory for Green Catalysis and Separation, and College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China
| | - Yuxi Liu
- Key Laboratory of Beijing on Regional Air Pollution Control, Beijing Key Laboratory for Green Catalysis and Separation, and College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China
| | - Hongxing Dai
- Key Laboratory of Beijing on Regional Air Pollution Control, Beijing Key Laboratory for Green Catalysis and Separation, and College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China
| | - Haibao Huang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Jiguang Deng
- Key Laboratory of Beijing on Regional Air Pollution Control, Beijing Key Laboratory for Green Catalysis and Separation, and College of Environmental and Energy Engineering, Beijing University of Technology, Beijing, 100124, China.
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13
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Abstract
The search for renewable and clean energy sources is a key aspect for sustainable development as energy consumption has continuously increased over the years concomitantly with environmental concerns caused by the use of fossil fuels. Semiconductor materials have great potential for acting as photocatalysts for solar fuel production, a potential energy source able to solve both energy and environmental concerns. Among the studied semiconductor materials, those based on niobium pentacation are still shallowly explored, although the number of publications and patents on Nb(V)-based photocatalysts has increased in the last years. A large variety of Nb(V)-based materials exhibit suitable electronic/morphological properties for light-driving reactions. Not only the extensive group of Nb2O5 polymorphs is explored, but also many types of layered niobates, mixed oxides, and Nb(V)-doped semiconductors. Therefore, the aim of this manuscript is to provide a review of the latest developments of niobium based photocatalysts for energy conversion into fuels, more specifically, CO2 reduction to hydrocarbons or H2 evolution from water. Additionally, the main strategies for improving the photocatalytic performance of niobium-based materials are discussed.
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14
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Mamaghani AH, Haghighat F, Lee CS. Hydrothermal/solvothermal synthesis and treatment of TiO 2 for photocatalytic degradation of air pollutants: Preparation, characterization, properties, and performance. CHEMOSPHERE 2019; 219:804-825. [PMID: 30572234 DOI: 10.1016/j.chemosphere.2018.12.029] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/26/2018] [Accepted: 12/05/2018] [Indexed: 06/09/2023]
Abstract
Photocatalytic oxidation (PCO) is a well-known technology for air purification and has been extensively studied for removal of many air pollutants. Titanium dioxide (TiO2) is the most investigated photocatalyst in the field of environmental remediation owed to its chemical stability, non-toxicity, and suitable positions of valence and conduction bands. Various preparation techniques including sol-gel, flame hydrolysis, water-in-oil microemulsion, chemical vapour deposition, solvothermal, and hydrothermal have been employed to obtain TiO2 materials. Hydro-/Solvothermal (HST) synthesis, focus of the present work, can be defined as a preparation method in which crystal growth occurs in a solvent at relatively low temperature (<200 °C) and above atmospheric pressure. This paper aims to provide a comprehensive and critical review of current knowledge regarding the application of HST synthesis for fabrication of TiO2 nanostructures for indoor air purification. TiO2 nanostructures are categorized from the morphological standpoint (e.g. nanoparticles, nanotubes, nanosheets, and hierarchically porous) and discussed in detail. The influence of preparation parameters including hydrothermal time, temperature, pH of the reaction medium, solvent, and calcination temperature on physical, chemical, and optical properties of TiO2 is reviewed. Considering the complex interplay among catalyst properties, a special emphasis is placed on elucidating the interconnection between various photocatalyst features and their impacts on photocatalytic activity.
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Affiliation(s)
| | - Fariborz Haghighat
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Canada.
| | - Chang-Seo Lee
- Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Canada.
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15
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Henych J, Mattsson A, Tolasz J, Štengl V, Österlund L. Solar light decomposition of warfare agent simulant DMMP on TiO2/graphene oxide nanocomposites. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00059c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Solar light-induced photodecomposition of organophosphorus warfare agent simulant dimethyl methylphosphonate (DMMP) on the surfaces of TiO2/graphene oxide (GO) nanocomposites was studied by in situ DRIFT spectroscopy.
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Affiliation(s)
- Jiří Henych
- Materials Chemistry Department
- Institute of Inorganic Chemistry of the Czech Academy of Sciences
- 25068 Řež
- Czech Republic
| | - Andreas Mattsson
- Department of Engineering Sciences
- The Ångström Laboratory
- Uppsala University
- SE-751 21 Uppsala
- Sweden
| | - Jakub Tolasz
- Materials Chemistry Department
- Institute of Inorganic Chemistry of the Czech Academy of Sciences
- 25068 Řež
- Czech Republic
| | - Václav Štengl
- Materials Chemistry Department
- Institute of Inorganic Chemistry of the Czech Academy of Sciences
- 25068 Řež
- Czech Republic
| | - Lars Österlund
- Department of Engineering Sciences
- The Ångström Laboratory
- Uppsala University
- SE-751 21 Uppsala
- Sweden
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16
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Min Y, Yang X, Wang D, Yang K, Zheng S, Li S, Chen H, Liang J, Pan F. Tuning mixed-phase Nb-doped titania films for high-performance photocatalysts with enhanced whole-spectrum light absorption. Catal Sci Technol 2019. [DOI: 10.1039/c9cy00745h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Heterojunction of rutile and anatase phase enhanced photocatalytic performance of mixed-phase Nb doped titania films to degrade pollutants under visible (vis) light.
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Affiliation(s)
- Yuxin Min
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Xiaoyang Yang
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Dawei Wang
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Kai Yang
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Shisheng Zheng
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Shunning Li
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Haibiao Chen
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Jun Liang
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
| | - Feng Pan
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P.R. China
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17
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da Cunha TT, Silva IF, do Pim WD, Binatti I, do Nascimento GM, Stumpf HO, Santana GC, Oliveira LCA, Pereira CLM. Multifunctional Nb–Cu nanostructured materials as potential adsorbents and oxidation catalysts for real wastewater decontamination. NEW J CHEM 2019. [DOI: 10.1039/c9nj01427f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hybrid oxidation catalysts and adsorbent materials containing niobium(v)–copper(ii) for the decontamination of real wastewater containing organic pollutants are reported herein.
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Affiliation(s)
- Tamyris T. da Cunha
- Departamento de Química
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Ingrid F. Silva
- Departamento de Química
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Walace D. do Pim
- Departamento de Química
- Centro Federal de Educação Tecnológica de Minas Gerais
- Belo Horizonte
- Brazil
| | - Ildefonso Binatti
- Departamento de Química
- Centro Federal de Educação Tecnológica de Minas Gerais
- Belo Horizonte
- Brazil
| | | | - Humberto O. Stumpf
- Departamento de Química
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Gilcinéa C. Santana
- Escola de Veterinária
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
| | - Luiz C. A. Oliveira
- Departamento de Química
- ICEx
- Universidade Federal de Minas Gerais
- Belo Horizonte
- Brazil
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18
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Muñoz-Batista MJ, Ballari MM, Kubacka A, Alfano OM, Fernández-García M. Braiding kinetics and spectroscopy in photo-catalysis: the spectro-kinetic approach. Chem Soc Rev 2018; 48:637-682. [PMID: 30516217 DOI: 10.1039/c8cs00108a] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The combination of kinetic and spectroscopic tools has become a key scientific methodology for the understanding of catalytic behavior but its application in photocatalysis has inherent difficulties due to the nature of the energy source of the reaction. This review article provides an overview of its use by, first, presenting mechanistically derived kinetic formulations and spectroscopic data handling methods including intrinsic expressions for light and, second, highlighting representative examples of application. To do it we consider universal catalytic systems, particularly (although not exclusively) titania-based materials, and the most frequent hole and/or electron triggered reaction schemes. This review also provides a general framework to pave the way for the future progress of the spectro-kinetic approach in the photocatalysis area.
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Affiliation(s)
- Mario J Muñoz-Batista
- Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie, 2, 28049 Madrid, Spain. and Departamento de Química Orgánica, Universidad de Córdoba, Edif. Marie Curie, Ctra Nnal IV-A, Km 396, E14014, Córdoba, Spain
| | - María M Ballari
- Instituto de Desarrollo Tecnológico para la Industria Química (INTEC, UNL-CONICET), Güemes 3450, 3000, Santa Fe, Argentina.
| | - Anna Kubacka
- Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie, 2, 28049 Madrid, Spain.
| | - Orlando M Alfano
- Instituto de Desarrollo Tecnológico para la Industria Química (INTEC, UNL-CONICET), Güemes 3450, 3000, Santa Fe, Argentina.
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19
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Moreno-Marrodan C, Barbaro P, Caporali S, Bossola F. Low-Temperature Continuous-Flow Dehydration of Xylose Over Water-Tolerant Niobia-Titania Heterogeneous Catalysts. CHEMSUSCHEM 2018; 11:3649-3660. [PMID: 30106509 DOI: 10.1002/cssc.201801414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/27/2018] [Indexed: 06/08/2023]
Abstract
The sustainable conversion of vegetable biomass-derived feeds to useful chemicals requires innovative routes meeting environmental and economical criteria. The approach herein pursued is the synthesis of water-tolerant, unconventional solid acid monolithic catalysts based on a mixed niobia-titania skeleton building up a hierarchical open-cell network of meso- and macropores, and tailored for use under continuous-flow conditions. The materials were characterized by spectroscopic, microscopy, and diffraction techniques, showing a reproducible isotropic structure and an increasing Lewis/Brønsted acid sites ratio with increasing Nb content. The catalytic dehydration reaction of xylose to furfural was investigated as a representative application. The efficiency of the catalyst was found to be dramatically affected by the niobia content in the titania lattice. The presence of as low as 2 wt % niobium resulted in the highest furfural yield at 140 °C under continuous-flow conditions, by using H2 O/γ-valerolactone as a safe monophasic solvent system. The interception of a transient 2,5-anhydroxylose species suggested the dehydration process occurs via a cyclic intermediates mechanism. The catalytic activity and the formation of the anhydro intermediate were related to the Lewis acid sites (LAS)/Brønsted acid sites (BAS) ratio and indicated a significant contribution of xylose-xylulose isomerization. No significant catalyst deactivation was observed over 4 days usage.
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Affiliation(s)
- Carmen Moreno-Marrodan
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti Organo Metallici, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
| | - Pierluigi Barbaro
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti Organo Metallici, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
| | - Stefano Caporali
- Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Via Giusti 9, 50121, Firenze, Italy
- Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
| | - Filippo Bossola
- Consiglio Nazionale delle Ricerche, Istituto di Scienze e Tecnologie Molecolari, Via Golgi 19, 20133, Milano, Italy
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20
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Henych J, Štengl V, Mattsson A, Tolasz J, Österlund L. Chemical warfare agent simulant DMMP reactive adsorption on TiO 2/graphene oxide composites prepared via titanium peroxo-complex or urea precipitation. JOURNAL OF HAZARDOUS MATERIALS 2018; 359:482-490. [PMID: 30075367 DOI: 10.1016/j.jhazmat.2018.07.095] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 06/29/2018] [Accepted: 07/23/2018] [Indexed: 05/14/2023]
Abstract
Two water-based methods were used to produce TiO2/graphene oxide (GO) nanocomposites with 1 and 2 wt.% GO. Both procedures exclude the use of organometallic precursors, as well as the high-pressure and high-temperature treatments, which facilitate pure and energy efficient synthesis amenable for larger scale synthesis. Nanocomposites with narrow (<10 nm) and long spindle-like (<100 nm) TiO2 nanoparticles supported on GO flakes were obtained (TiO2/GO), and their properties for reactive destruction of the organophosphorus simile chemical warfare agent (CWA) dimethyl methylphosphonate (DMMP) were investigated by in situ DRIFTS spectroscopy. Both synthesis procedures yielded highly reactive nanocomposites with markedly different properties compared to similarly prepared pure TiO2 nanoparticles. GO also induced morphology and texture changes, which were observed to have a significant impact on the adsorption and reactivity of the nanocomposites, and which were strongly related to synthesis procedure. In particular, the reduction state of GO, as measured by Raman spectroscopy, was observed to play a major role for the reactivity of the TiO2/GO nanocomposites.
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Affiliation(s)
- Jiří Henych
- Materials Chemistry Department, Institute of Inorganic Chemistry, Czech Academy of Sciences, Husinec-Řež 1001, 250 68 Řež, Czech Republic.
| | - Václav Štengl
- Materials Chemistry Department, Institute of Inorganic Chemistry, Czech Academy of Sciences, Husinec-Řež 1001, 250 68 Řež, Czech Republic
| | - Andreas Mattsson
- Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, P.O. Box 534, SE-751 21 Uppsala, Sweden
| | - Jakub Tolasz
- Materials Chemistry Department, Institute of Inorganic Chemistry, Czech Academy of Sciences, Husinec-Řež 1001, 250 68 Řež, Czech Republic
| | - Lars Österlund
- Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, P.O. Box 534, SE-751 21 Uppsala, Sweden
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21
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Won Y, Schwartzenberg K, Gray KA. TiO 2-based transparent coatings create self-cleaning surfaces. CHEMOSPHERE 2018; 208:899-906. [PMID: 30068033 DOI: 10.1016/j.chemosphere.2018.06.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/01/2018] [Accepted: 06/02/2018] [Indexed: 06/08/2023]
Abstract
Implementation of self-cleaning surfaces is gaining attention as a tool to combat the healthcare associated infections (HAIs). In this study, we prepared TiO2-based transparent coatings as one such potential self-cleaning surface for touchscreen application and evaluated their antimicrobial efficacy under dark and illuminated conditions. To maintain high transparency and TiO2 coverage, clean borosilicate glass slides were dip-coated multiple times in a suspension of TiO2-based materials at a low concentration. The as-prepared samples were tested for their roughness and hydrophilicity via atomic force microscopy (AFM) and contact angle analysis, respectively. To screen the antimicrobial performance of the TiO2 coated samples, the number and viability of attached bacteria on the film surfaces were recorded after submerging them in a bacterial suspension for 45 min under dark or ultraviolet (UV) illuminated conditions. The antimicrobial performance of the commercially available regular and Ag-coated antimicrobial Corning® Gorilla® Glass were also evaluated under the same conditions and compared with those of the TiO2 coated samples. Among the test samples, n-Ag/TiO2 (<100 nm) coated samples achieved greater than 80% bactericidal efficacy with the lowest bacterial attachment after the UV exposure. TiO2-based transparent coatings show promise as an effective tool against bacterial attachment and displays greater bactericidal activity in comparison to commercial antibacterial glass.
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Affiliation(s)
- Yechan Won
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208-3109, USA
| | - Kevin Schwartzenberg
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208-3109, USA
| | - Kimberly A Gray
- Department of Civil and Environmental Engineering, Northwestern University, Evanston, IL 60208-3109, USA.
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22
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Yang X, Min Y, Li S, Wang D, Mei Z, Liang J, Pan F. Conductive Nb-doped TiO2 thin films with whole visible absorption to degrade pollutants. Catal Sci Technol 2018. [DOI: 10.1039/c7cy02614e] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Niobium-doping makes both intrinsic UV absorption and UV-vis-IR free-carrier absorption occur in TiO2 and improves the photocatalytic performance.
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Affiliation(s)
- Xiaoyang Yang
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P. R. China
| | - Yuxin Min
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P. R. China
| | - Sibai Li
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P. R. China
| | - Dawei Wang
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P. R. China
| | - Zongwei Mei
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P. R. China
| | - Jun Liang
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P. R. China
| | - Feng Pan
- School of Advanced Materials
- Peking University Shenzhen Graduate School
- Shenzhen 518055
- P. R. China
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23
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UV and visible light driven H 2 photo-production using Nb-doped TiO 2 : Comparing Pt and Pd co-catalysts. MOLECULAR CATALYSIS 2017. [DOI: 10.1016/j.mcat.2017.04.035] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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24
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Visible-light activation of TiO2 photocatalysts: Advances in theory and experiments. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2015. [DOI: 10.1016/j.jphotochemrev.2015.08.003] [Citation(s) in RCA: 749] [Impact Index Per Article: 83.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Stefanov B, Topalian Z, Granqvist C, Österlund L. Acetaldehyde adsorption and condensation on anatase TiO2: Influence of acetaldehyde dimerization. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcata.2013.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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26
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Gao M, Xu Y, Bai Y, Xiao F. Nb, F-codoped TiO2 hollow spheres with high visible light photocatalytic activity. NANOSCALE RESEARCH LETTERS 2013; 8:508. [PMID: 24305040 PMCID: PMC3879027 DOI: 10.1186/1556-276x-8-508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 11/18/2013] [Indexed: 06/02/2023]
Abstract
Nb, F-codoped TiO2 hollow spheres (NFTSs) were successfully synthesized via a hydrothermal method with niobium oxide, hydrofluoric acid, and tetrabutyl titanate. The obtained spheres were hollow, with a diameter of about 2 μm, and the sphere wall was made up of nanorods arranged close together. The NFTSs presented anatase phase with more {001} facets exposed, which could be mainly attributed to F ions which were preferentially adsorbed on the {001} facets during the crystal growth process. Ti3+ states in NFTSs were increased due to Nb, F-codoping, resulting in the decrease of the band gap and the red shift of the absorption edge of the NFTSs. The NFTSs exhibited 20.1% higher photocatalytic speed compared to P25 on the degradation of methylene orange.
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Affiliation(s)
- Mingqi Gao
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
| | - Youlong Xu
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yang Bai
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
| | - Fang Xiao
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an 710049, China
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27
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Chua CS, Fang X, Chen X, Tan OK, Tse MS, Soutar AM, Ding X. Effect of Annealing Temperature on Microstructure and UV Light Photocatalytic Activity of TiO2Films Grown by Atmospheric Pressure CVD. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/cvde.201207015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Chin Sheng Chua
- School of Electrical and Electronic Engineering; Nanyang Technological University; 50 Nanyang Avenue Singapore 639798 (Singapore)
| | - Xiaoqin Fang
- School of Electrical and Electronic Engineering; Nanyang Technological University; 50 Nanyang Avenue Singapore 639798 (Singapore)
| | - Xiaofeng Chen
- School of Electrical and Electronic Engineering; Nanyang Technological University; 50 Nanyang Avenue Singapore 639798 (Singapore)
| | - Ooi Kiang Tan
- School of Electrical and Electronic Engineering; Nanyang Technological University; 50 Nanyang Avenue Singapore 639798 (Singapore)
| | - Man Siu Tse
- School of Electrical and Electronic Engineering; Nanyang Technological University; 50 Nanyang Avenue Singapore 639798 (Singapore)
| | - Andrew McIntosh Soutar
- Singapore Institute of Manufacturing Technology; 71 Nanyang Drive Singapore 638075 (Singapore)
| | - Xingzhao Ding
- Singapore Institute of Manufacturing Technology; 71 Nanyang Drive Singapore 638075 (Singapore)
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28
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Topalian Z, Stefanov B, Granqvist C, Österlund L. Adsorption and photo-oxidation of acetaldehyde on TiO2 and sulfate-modified TiO2: Studies by in situ FTIR spectroscopy and micro-kinetic modeling. J Catal 2013. [DOI: 10.1016/j.jcat.2013.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Jiang L, You T, Deng WQ. Enhanced photovoltaic performance of a quantum dot-sensitized solar cell using a Nb-doped TiO2 electrode. NANOTECHNOLOGY 2013; 24:415401. [PMID: 24045808 DOI: 10.1088/0957-4484/24/41/415401] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this work Nb-doped anatase TiO2 nanocrystals are used as the photoanode of quantum-dot-sensitized solar cells. A solar cell with CdS/CdSe quantum dots co-sensitized 2.5 mol% Nb-doped anatase TiO2 nanocrystals can achieve a photovoltaic conversion efficiency of 3.3%, which is almost twice as high as the 1.7% obtained by a cell based on undoped TiO2 nanocrystals. The incident photon-to-current conversion efficiency can reach as high as 91%, which is a record for all quantum-dot-sensitized solar cells. Detailed analysis shows that such an enhancement is due to improved lifetime and diffusion length of electrons in the solar cell.
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Affiliation(s)
- Lei Jiang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
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30
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Nisar J, Topalian Z, De Sarkar A, Österlund L, Ahuja R. TiO2-based gas sensor: a possible application to SO2. ACS APPLIED MATERIALS & INTERFACES 2013; 5:8516-8522. [PMID: 23915321 DOI: 10.1021/am4018835] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Fixation of SO2 molecules on anatase TiO2 surfaces with defects have been investigated by first-principles density functional theory (DFT) calculations and in situ Fourier transform infrared (FTIR) surface spectroscopy on porous TiO2 films. Intrinsic oxygen-vacancy defects, which are formed on TiO2(001) and TiO2(101) surfaces by ultraviolet (UV) light irradiation and at elevated temperatures, are found to be most effective in anchoring the SO2 gas molecules to the TiO2 surfaces. Both TiO2(101) and TiO2(001) surfaces with oxygen vacancies are found to exhibit higher SO2 adsorption energies in the DFT calculations. The adsorption mechanism of SO2 is explained on the basis of electronic structure, charge transfer between the molecule and the surface, and the oxidation state of the adsorbed molecule. The theoretical findings are corroborated by FTIR experiments. Moreover, the (001) surface with oxygen vacancies is found to bind SO2 gas molecules more strongly, as compared to the (101) surface. Higher concentration of oxygen vacancies on the TiO2 surfaces is found to significantly increase the adsorption energy. The results shed new insight into the sensing properties of TiO2-based gas sensors.
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Affiliation(s)
- Jawad Nisar
- Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University , Box 516, SE-751 20 Uppsala, Sweden
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Mattsson A, Lejon C, Bakardjieva S, Štengl V, Österlund L. Characterisation, phase stability and surface chemical properties of photocatalytic active Zr and Y co-doped anatase TiO2 nanoparticles. J SOLID STATE CHEM 2013. [DOI: 10.1016/j.jssc.2012.12.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Kim SG, Ju MJ, Choi IT, Choi WS, Choi HJ, Baek JB, Kim HK. Nb-doped TiO2 nanoparticles for organic dye-sensitized solar cells. RSC Adv 2013. [DOI: 10.1039/c3ra42081g] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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33
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Michalow KA, Flak D, Heel A, Parlinska-Wojtan M, Rekas M, Graule T. Effect of Nb doping on structural, optical and photocatalytic properties of flame-made TiO2 nanopowder. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2012; 19:3696-3708. [PMID: 23054731 DOI: 10.1007/s11356-012-0953-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 04/24/2012] [Indexed: 06/01/2023]
Abstract
TiO(2):Nb nanopowders within a dopant concentration in the range of 0.1-15 at.% were prepared by one-step flame spray synthesis. Effect of niobium doping on structural, optical and photocatalytic properties of titanium dioxide nanopowders was studied. Morphology and structure were investigated by means of Brunauer-Emmett-Teller isotherm, X-ray diffraction and transmission electron microscopy. Diffuse reflectance and the resulting band gap energy were determined by diffuse reflectance spectroscopy. Photocatalytic activity of the investigated nanopowders was revised for the photodecomposition of methylene blue (MB), methyl orange (MO) and 4-chlorophenol under UVA and VIS light irradiation. Commercial TiO(2)-P25 nanopowder was used as a reference. The specific surface area of the powders was ranging from 42.9 m(2)/g for TiO(2):0.1 at.% Nb to 90.0 m(2)/g for TiO(2):15 at.% Nb. TiO(2):Nb particles were nanosized, spherically shaped and polycrystalline. Anatase was the predominant phase in all samples. The anatase-related transition was at 3.31 eV and rutile-related one at 3.14 eV. TiO(2):Nb nanopowders exhibited additional absorption in the visible range. In comparison to TiO(2)-P25, improved photocatalytic activity of TiO(2):Nb was observed for the degradation of MB and MO under both UVA and VIS irradiation, where low doping level (Nb < 1 at.%) was the most effective. Niobium doping affected structural, optical and photocatalytic properties of TiO(2). Low dopant level enhanced photocatalytic performance under UVA and VIS irradiation. Therefore, TiO(2):Nb (Nb < 1 at.%) can be proposed as an efficient selective solar light photocatalyst.
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Affiliation(s)
- Katarzyna A Michalow
- Laboratory for High Performance Ceramics, Empa Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600, Duebendorf, Switzerland.
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Chen H, Nanayakkara CE, Grassian VH. Titanium Dioxide Photocatalysis in Atmospheric Chemistry. Chem Rev 2012; 112:5919-48. [DOI: 10.1021/cr3002092] [Citation(s) in RCA: 614] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Haihan Chen
- Departments
of Chemical and Biochemical Engineering and §Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Charith E. Nanayakkara
- Departments
of Chemical and Biochemical Engineering and §Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Vicki H. Grassian
- Departments
of Chemical and Biochemical Engineering and §Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
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Lin KL, Mai FD, Chan YC, Chung JC, Lin KM, Yu CC, Liao MY, Li FY. Morphology Dependence of Photocatalytic Activity of TiO2 Nanostructure Prepared through Microwave Hydrothermal Process. J CHIN CHEM SOC-TAIP 2012. [DOI: 10.1002/jccs.201100522] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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36
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Topalian Z, Niklasson GA, Granqvist CG, Österlund L. Spectroscopic study of the photofixation of SO2 on anatase TiO2 thin films and their oleophobic properties. ACS APPLIED MATERIALS & INTERFACES 2012; 4:672-679. [PMID: 22204641 DOI: 10.1021/am201253y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Photoinduced SO(2) fixation on anatase TiO(2) films was studied by in situ Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The TiO(2) films were prepared by reactive DC magnetron sputtering and were subsequently exposed to 50 ppm SO(2) gas mixed in synthetic air and irradiated with UV light at substrate temperatures between 298 and 673 K. Simultaneous UV irradiation and SO(2) exposure between 373 and 523 K resulted in significant sulfur (S) deposits on crystalline TiO(2) films as determined by XPS, whereas amorphous films contained negligible amounts of S. At substrate temperatures above 523 K, the S deposits readily desorbed from TiO(2). The oxidation state of sulfur successively changed from S(4+) for SO(2) adsorbed on crystalline TiO(2) films at room temperature without irradiation to S(6+) for films exposed to SO(2) at elevated temperatures with simultaneous irradiation. In situ FTIR was used to monitor the temporal evolution of the photoinduced surface reaction products formed on the TiO(2) surfaces. It is shown that band gap excitation of TiO(2) results in photoinduced oxidation of SO(2), which at elevated temperatures become coordinated to the TiO(2) lattice through interactions with O vacancies and form sulfite and sulfate surface species. These species makes the surface acidic, which is manifested in nondetectable adherence of stearic acid to the modified surface. The modified films show good chemical stability as evidenced by sonication and repeated recycling of the films. The results suggest a new method to functionalize wide band gap oxide surfaces by means of photoinduced reactions in reactive gases at elevated substrate temperatures. In the case of anatase TiO(2) in reactive SO(2) gas, we here show that such functionalization yields surfaces with excellent oleophobic properties, as probed by adhesion of stearic acid.
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Affiliation(s)
- Z Topalian
- Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, PO Box 534, SE-751 21 Uppsala, Sweden.
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37
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Kubacka A, Fernández-García M, Colón G. Advanced Nanoarchitectures for Solar Photocatalytic Applications. Chem Rev 2011; 112:1555-614. [DOI: 10.1021/cr100454n] [Citation(s) in RCA: 1901] [Impact Index Per Article: 146.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Anna Kubacka
- Instituto de Catálisis y Petroleoquímica, CSIC, C/Marie Curie 2, 28049-Madrid, Spain
| | | | - Gerardo Colón
- Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad de Sevilla, C/Américo Vespucio, 49, 41092-Sevilla, Spain
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Kronawitter CX, Bakke JR, Wheeler DA, Wang WC, Chang C, Antoun BR, Zhang JZ, Guo J, Bent SF, Mao SS, Vayssieres L. Electron enrichment in 3d transition metal oxide hetero-nanostructures. NANO LETTERS 2011; 11:3855-3861. [PMID: 21834542 DOI: 10.1021/nl201944h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Direct experimental observation of spontaneous electron enrichment of metal d orbitals in a new transition metal oxide heterostructure with nanoscale dimensionality is reported. Aqueous chemical synthesis and vapor phase deposition are combined to fabricate oriented arrays of high-interfacial-area hetero-nanostructures comprised of titanium oxide and iron oxide nanomaterials. Synchrotron-based soft X-ray spectroscopy techniques with high spectral resolution are utilized to directly probe the titanium and oxygen orbital character of the interfacial region's occupied and unoccupied densities of states. These data demonstrate the interface to possess electrons in Ti 3d bands and an emergent degree of orbital hybridization that is absent in parent oxide reference crystals. The carrier dynamics of the hetero-nanostructures are studied by ultrafast transient absorption spectroscopy, which reveals the presence of a dense manifold of states, the relaxations from which exhibit multiple exponential decays whose magnitudes depend on their energetic positions within the electronic structure.
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Affiliation(s)
- Coleman X Kronawitter
- Department of Mechanical Engineering, University of California at Berkeley, Berkeley, California 94720, United States
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40
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Mei B, Sánchez MD, Reinecke T, Kaluza S, Xia W, Muhler M. The synthesis of Nb-doped TiO2 nanoparticles by spray drying: an efficient and scalable method. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm11431j] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Wan L, Li X, Qu Z, Shi Y, Li H, Zhao Q, Chen G. Facile synthesis of ZnO/Zn2TiO4 core/shell nanowires for photocatalytic oxidation of acetone. JOURNAL OF HAZARDOUS MATERIALS 2010; 184:864-868. [PMID: 20810213 DOI: 10.1016/j.jhazmat.2010.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 07/14/2010] [Accepted: 08/03/2010] [Indexed: 05/29/2023]
Abstract
ZnO/Zn(2)TiO(4) core/shell nanowires were synthesized for the first time based on a solid-solid reaction of ZnO nanowires with a conformal shell of TiO(2), which was deposited by a sol-gel method. The as-prepared samples were characterized by X-ray diffraction (XRD) analysis, transmission electron microscope (TEM) and environmental scanning electron microscope (ESEM). The surface photovoltage (SPV) spectra indicated that the as-synthesized ZnO/Zn(2)TiO(4) core/shell nanowires exhibited more excellent photovoltaic activity than single ZnO nanowires. The enhanced photocatalytic activity of the ZnO/Zn(2)TiO(4) core/shell nanowires was demonstrated by the degradation of acetone under UV light irradiation. As monitored by the in situ FTIR, a sequence of chemical steps could be extracted during the photocatalytic oxidation of gaseous acetone, which was firstly degraded into formate, and subsequently converted into CO and CO(2). CO(2) was partially converted to carbonate further.
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Affiliation(s)
- Liyuan Wan
- Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024, China
| | - Xinyong Li
- Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024, China; Department of Chemical and Biomolecular Engineering, the Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China.
| | - Zhenping Qu
- Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024, China
| | - Yong Shi
- Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024, China
| | - Hong Li
- Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024, China
| | - Qidong Zhao
- Key Laboratory of Industrial Ecology and Environmental Engineering and State Key Laboratory of Fine Chemical, School of Environmental Science & Technology, Dalian University of Technology, Dalian, 116024, China
| | - Guohua Chen
- Department of Chemical and Biomolecular Engineering, the Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
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42
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Liu Y, Szeifert JM, Feckl JM, Mandlmeier B, Rathousky J, Hayden O, Fattakhova-Rohlfing D, Bein T. Niobium-doped titania nanoparticles: synthesis and assembly into mesoporous films and electrical conductivity. ACS NANO 2010; 4:5373-5381. [PMID: 20734979 DOI: 10.1021/nn100785j] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Crystalline niobium-doped titania nanoparticles were synthesized via solvothermal procedures using tert-butyl alcohol as a novel reaction medium, and their assembly into mesoporous films was investigated. The solvothermal procedure enables the preparation of crystalline doped and undoped nonagglomerated titania nanoparticles, whose size can be controlled from 4 to 15 nm by changing the reaction temperature and time. The anatase lattice of these particles can incorporate more than 20 mol % of Nb ions. The nanoparticles can be easily dispersed at high concentrations in THF to form stable colloidal suspensions and can be assembled into uniform porous mesostructures directed by the commercial Pluronic block copolymer F127. The resulting mesoporous films show a regular mesostructure with a d spacing of about 17 nm, a uniform pore size of about 10 nm with crystalline walls, a high porosity of 43%, and a large surface area of 190 m(2) cm(-3). Substitutional doping with niobium ions drastically increases the electrical conductivity of the titania particles. The electrical conductivity of as-prepared nanoparticles containing 20 mol % of Nb is 2 x 10(-5) S cm(-1); it increases to 0.25 S cm(-1) after treatment at 600 °C in nitrogen.
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Affiliation(s)
- Yujing Liu
- Department of Chemistry and Center for NanoScience (CeNS), University of Munich (LMU), Butenandtstrasse 5-13, 81377 Munich, Germany
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Structure-Reactivity Relationships of Anatase and Rutile TiO 2 Nanocrystals Measured by In Situ Vibrational Spectroscopy. ACTA ACUST UNITED AC 2010. [DOI: 10.4028/www.scientific.net/ssp.162.203] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A comprehensive analysis of structural-reactivity relations on TiO2 nanocrystals is presented. Using an interplay between TEM, X-ray diffraction and vibrational spectroscopy of well-defined anatase and rutile TiO2 nanocrystals correlations between the adsorbate structure of formic acid and the corresponding photo-induced decomposition rate are described. It is demonstrated that the detailed bonding configuration determines the decomposition rate. Generalizations and implications of the findings are discussed.
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Lu X, Zhang HP, Leng Y, Fang L, Qu S, Feng B, Weng J, Huang N. The effects of hydroxyl groups on Ca adsorption on rutile surfaces: a first-principles study. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:1-10. [PMID: 19639267 DOI: 10.1007/s10856-009-3828-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Accepted: 07/14/2009] [Indexed: 05/28/2023]
Abstract
Hydroxyl groups on titanium surfaces have been believed to play an important role in absorbing Ca in solution, which is crucial in the formation of bioactive calcium phosphates both in vitro and in vivo. CASTEP, a first-principles density functional theory (DFT) code, was employed to investigate Ca adsorption on various rutile (110) surfaces in order to clarify how hydroxyl groups effect Ca adsorption. The surfaces modeled in the present study include a bare rutile (110) surface, a hydroxylated rutile (110) surface, an oxidized rutile (110) surface, and a rutile (110) surface bonded with mixed OH groups and water. The results reveal that not all OH groups favors to attract Ca adsorption and loosely bonded OH and water on a rutile surface actually combine with Ca during adsorption. An oxidized rutile surface has the highest ability to attract Ca atoms, which partially explains that alkali-treated Ti surfaces could induce hydroxyapatite formation in alkaline environments.
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Affiliation(s)
- Xiong Lu
- Department of Mechanical Engineering, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China.
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46
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Chen J, Poon CS. Photocatalytic activity of titanium dioxide modified concrete materials - influence of utilizing recycled glass cullets as aggregates. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2009; 90:3436-42. [PMID: 19540649 DOI: 10.1016/j.jenvman.2009.05.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 05/04/2009] [Accepted: 05/22/2009] [Indexed: 05/10/2023]
Abstract
Combining the use of photocatalysts with cementitious materials is an important development in the field of photocatalytic air pollution mitigation. This paper presents the results of a systematic study on assessing the effectiveness of pollutant degradation by concrete surface layers that incorporate a photocatalytic material - Titanium Dioxide. The photocatalytic activity of the concrete samples was determined by photocatalytic oxidation of nitric oxide (NO) in the laboratory. Recycled glass cullets, derived from crushed waste beverage bottles, were used to replace sand in preparing the concrete surface layers. Factors, which may affect the pollutant removal performance of the concrete layers including glass color, aggregate size and curing age, were investigated. The results show a significant enhancement of the photocatalytic activity due to the use of glass cullets as aggregates in the concrete layers. The samples fabricated with clear glass cullets exhibited threefold NO removal efficiency compared to the samples fabricated with river sand. The light transmittance property of glass was postulated to account for the efficiency improvement, which was confirmed by a separate simulation study. But the influence of the size of glass cullets was not evident. In addition, the photocatalytic activity of concrete surface layers decreased with curing age, showing a loss of 20% photocatalytic activity after 56-day curing.
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Affiliation(s)
- Jun Chen
- Department of Civil and Structural Engineering, Research Center for Environmental Technology and Management, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
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47
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Castro A, Nunes M, Carvalho M, Ferreira L, Jumas JC, Costa F, Florêncio M. Doped titanium dioxide nanocrystalline powders with high photocatalytic activity. J SOLID STATE CHEM 2009. [DOI: 10.1016/j.jssc.2009.04.020] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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48
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King R, Idriss H. Acetone reactions over the surfaces of polycrystalline UO2: a kinetic and spectroscopic study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4543-4555. [PMID: 19366223 DOI: 10.1021/la803933t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The reaction of acetone is studied on the surfaces of polycrystalline UO2, prepared by hydrogen reduction of U3O8 at 770 K. The study is conducted by in situ Fourier transform infrared (FTIR) and temperature-programmed desorption (TPD). Acetone adsorption does not fit the simple Langmuir model, and adsorbate-adsorbate interactions are found to be significant. Acetone adsorbs molecularly on UO2 as evidenced by the nuCO of the eta1(O) mode at 1686 cm(-1). Part of acetone is reduced to the isopropoxide species ((CH3)2HC-O-U4+) upon heating (nu(CC), rho(CH3) at 1167 cm(-1) and nu(CO), rho(CH3) at 980 cm(-1)), and upon further heating, acetates (CH3COO(a), (a) for adsorbed) are observed. Detailed TPD studies indicated that the main reaction of acetone on UO2 is the deoxygenation to propene, driven by the oxophilic nature of UO2. Other reactions were also observed to a lesser extent, and these included reductive coupling to 2,3-dimethylbutene and condensation to mesityl oxide. An attempt to extract kinetic parameters from TPD data was conducted. Three models were studied: variation of heating rate, leading edge analysis (Habenschaden-Kuppers method), and complete analysis. The complete analysis provided the most plausible results, in particular, at low coverage. With this method, at nearly zero coverage the activation energy, Ed, for desorption was found to be close to 140 kJ/mol with a prefactor of 10(13) s(-1). Ed dropped sharply with increasing coverage, theta, to ca. 35 kJ/mol at theta=0.15 with a prefactor of 10(11) s(-1). The activation energy for the desorption of acetone on UO2(111) single crystals, at saturation coverage, was previously found to be equal to 65 kJ/mol using the leading edge analysis.
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Affiliation(s)
- Richard King
- Department of Chemistry, The University of Auckland, Auckland, New Zealand
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Schmidt CM, Buchbinder AM, Weitz E, Geiger FM. Photochemistry of the Indoor Air Pollutant Acetone on Degussa P25 TiO2Studied by Chemical Ionization Mass Spectrometry. J Phys Chem A 2007; 111:13023-31. [DOI: 10.1021/jp076745+] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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50
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Preparation and characterization of Nb-doped TiO2 nanoparticles used as a conductive support for bifunctional CuCo2O4 electrocatalyst. J Electroanal Chem (Lausanne) 2007. [DOI: 10.1016/j.jelechem.2007.08.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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