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Liu Y, Zhong W, Yang C, Liu X, Cheng Q, Tan T, Deng Q, Yang C. Defective state regulation of Ru-doped Nb 2O 5 boosts fast lithium storage. J Colloid Interface Sci 2024; 667:136-146. [PMID: 38636215 DOI: 10.1016/j.jcis.2024.04.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 03/13/2024] [Accepted: 04/04/2024] [Indexed: 04/20/2024]
Abstract
Breaking through the limitations of lithium-ion transmission is imperative for high-power rechargeable batteries. As a promising anode material for fast-charging lithium-ion batteries (LIBs), niobium pentoxide (Nb2O5) has garnered considerable research attention due to its exceptional rate performance, stable lithium storage performance and high safety attributes. Nevertheless, the limited intrinsic conductivity of Nb2O5, coupled with its structural degradation during the cycling process, imposes constraints on its viability as a commercially viable electrode material. Herein, a ruthenium (Ru) doping method is employed to regulate the oxygen defects and the interlayer spacing of the tetragonal Nb2O5 (M-Nb2O5), offering superior reaction kinetics, higher stability for lithium storage sites and more unobstructed lithium-ion transport channels. Ru-doped Nb2O5 (RNO) manifests excellent electrochemical properties, including remarkable rate capacity (166 mAh/g at 80C), reversible capacity (246.98 mAh/g at 0.5C), improved initial Coulombic efficiency (95.77 % compared to 81.44 % of the pure sample) and cycling stability (maintaining a capacity of 113.5 mAh/g at 10C for 2,000 cycles). The enhancement mechanism of Ru doping on the structural stability and ion transport kinetics in tetragonal Nb2O5 is comprehensively elucidated through diverse electrochemical analyses and in-situ techniques.
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Affiliation(s)
- Yuqiao Liu
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Wentao Zhong
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Cuiyun Yang
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xiaozhao Liu
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Qian Cheng
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Ting Tan
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Qiang Deng
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Chenghao Yang
- Guangzhou Key Laboratory for Surface Chemistry of Energy Materials, New Energy Research Institute, School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
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Olusegun SJ, Rodrigues GLS, Tiwari S, Krajewski M, Mohallem NDS, Sobczak K, Donten M, Krysinski P. Removal of doxorubicin hydrochloride and crystal violet from aqueous solutions using spray-dried niobium oxide coated with chitosan-activated carbon: Experimental and DFT calculations. Int J Biol Macromol 2024; 266:131158. [PMID: 38552682 DOI: 10.1016/j.ijbiomac.2024.131158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 09/21/2023] [Accepted: 03/25/2024] [Indexed: 04/07/2024]
Abstract
Spray-dried niobium oxide coated with chitosan-activated carbon (NIC) was synthesized and used to remove doxorubicin hydrochloride and crystal violet from aqueous solutions under different parameters such as solution pH (2, 4, 6, and 8), contact time (1 to 9 h), initial concentration (20 to 200 mg L-1), and competing ions (0.1 M of CaCl2 and NaCl). The addition of 5 % chitosan-activated carbon to the matrix of niobium oxide slightly increased the specific surface area from 26 to 30 m2 g-1, with the introduction of a carboxylic functional group. This led to an increase in the amount of adsorbed doxorubicin hydrochloride (DOH) from 30 to 44 mg g-1 and that of crystal violet (CV) from 15 to 32 mg g-1 from the initial respective 100 mg L-1 at pH 8. The data from the concentration study fitted into Liu isotherm having adsorption capacity of 128 and 57 mg g-1 for DOH and CV respectively, while pseudo first and second order are more suitable for adsorption kinetics. The additional functional groups on the IR spectrum of NIC after the adsorption of DOH and CV confirmed the interaction between NIC and the adsorbates' molecules. The mechanism of adsorption was supported by DFT calculations.
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Affiliation(s)
- Sunday J Olusegun
- Department of Environmental Biotechnology, Faculty of Energy and Environmental Engineering, Silesian University of Technology, Gliwice, Poland..
| | - Gabriel L S Rodrigues
- Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - Santosh Tiwari
- Department of Chemistry, Nitte Mahalinga Adyanthaya Memorial Institute of Technology, Mangaluru, Karnataka 547110, India
| | | | - Nelcy D S Mohallem
- Universidade Federal de Minas Gerais, Departamento de Química, Laboratório de Materiais Nanoestruturados, Belo Horizonte, MG, Brazil
| | - Kamil Sobczak
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Mikołaj Donten
- Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Pawel Krysinski
- Faculty of Chemistry, University of Warsaw, Warsaw, Poland..
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Kim HY, Cho JH, Yoon HI, Lee JH, Choi S, Han JS, Yeo ISL. Topographical and crystalline change on surface by sandblasting improve flexural and shear bond strength of niobia-modified yttria-stabilized tetragonal zirconia polycrystal. Dent Mater J 2024; 43:216-226. [PMID: 38417860 DOI: 10.4012/dmj.2023-225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
This study aimed to investigate the effects of sandblasting on the physical properties and bond strength of two types of translucent zirconia: niobium-oxide-containing yttria-stabilized tetragonal zirconia polycrystals ((Y, Nb)-TZP) and 5 mol% yttria-partially stabilized zirconia (5Y-PSZ). Fully sintered disc specimens were either sandblasted with 125 µm alumina particles or left as-sintered. Surface roughness, crystal phase compositions, and surface morphology were explored. Biaxial flexural strength (n=10) and shear bond strength (SBS) (n=12) were evaluated, including thermocycling conditions. Results indicated a decrease in flexural strength of 5Y-PSZ from 601 to 303 MPa upon sandblasting, while (Y, Nb)-TZP improved from 458 to 544 MPa. Both materials significantly increased SBS after sandblasting (p<0.001). After thermocycling, (Y, Nb)-TZP maintained superior SBS (14.3 MPa) compared to 5Y-PSZ (11.3 MPa) (p<0.001). The study concludes that (Y, Nb)-TZP is preferable for sandblasting applications, particularly for achieving durable bonding without compromising flexural strength.
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Affiliation(s)
- Ha-Young Kim
- Department of Prosthodontics, Seoul National University School of Dentistry
| | - Jun-Ho Cho
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University
| | - Hyung-In Yoon
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University
| | - Jae-Hyun Lee
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University
| | - Sunyoung Choi
- Department of Prosthodontics, One-Stop Specialty Center, Seoul National University Dental Hospital
| | - Jung-Suk Han
- Department of Prosthodontics, Seoul National University School of Dentistry
| | - In-Sung Luke Yeo
- Department of Prosthodontics, School of Dentistry and Dental Research Institute, Seoul National University
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Rameel MI, Wali M, Al-Humaidi JY, Liaqat F, Khan MA. Enhanced photocatalytic degradation of levofloxacin over heterostructured C 3N 4/Nb 2O 5 system under visible light. Heliyon 2023; 9:e20479. [PMID: 37800069 PMCID: PMC10550519 DOI: 10.1016/j.heliyon.2023.e20479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/25/2023] [Accepted: 09/26/2023] [Indexed: 10/07/2023] Open
Abstract
The growing usage of antibiotics and their subsequent release in water bodies have become a serious environmental concern. In this study, heterostructured photocatalysts C3N4/Nb2O5 have been synthesized using a simple hydrothermal method and applied to facilitate the degradation of the widely used antibiotic levofloxacin. The structural, morphological, and optical properties of the photocatalysts were characterized using XRD, SEM, TEM, UV-Vis and PL to establish the structure-property relationship. The type-II heterojunctions C3N4/Nb2O5 show remarkable activity under visible light irradiation, where Nb2O5 facilitates preferential adsorption of levofloxacin at the catalyst surface while C3N4 extends visible light absorption. This synergy resulted in superior catalytic performance (91%) in the optimized system, exceeding that of individual materials (Nb2O5 30% and C3N4 56%). The effect of catalyst dosage, pH, oxygen and point of zero is also investigated. The process is mainly photo-driven, and the trapping experiments reveal superoxide radicals as key species responsible for the degradation. Additionally, the adsorption behaviour, reformation of the degraded pollutant and reusability factors are evaluated to assess the practical feasibility of the photocatalytic system.
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Affiliation(s)
- Muhammad Imran Rameel
- Renewable Energy Advancement Laboratory (REAL), Department of Environmental Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Mehar Wali
- Renewable Energy Advancement Laboratory (REAL), Department of Environmental Sciences, Quaid-i-Azam University Islamabad, Pakistan
| | - Jehan Y Al-Humaidi
- Department of Chemistry College of Science Princess Nourah bint Abdulrahman University. P.O. BOX 84428, Riyadh 11671, Saudi Arabia
| | - Faroha Liaqat
- Department of Chemistry, Quaid-i-Azam University Islamabad, Pakistan
| | - Muhammad Abdullah Khan
- Renewable Energy Advancement Laboratory (REAL), Department of Environmental Sciences, Quaid-i-Azam University Islamabad, Pakistan
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5
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Park W, Kim G, In JH, Rhee H, Song H, Park J, Martinez A, Kim KM. High Amplitude Spike Generator in Au Nanodot-Incorporated NbO x Mott Memristor. Nano Lett 2023; 23:5399-5407. [PMID: 36930534 DOI: 10.1021/acs.nanolett.2c04599] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
NbOx-based Mott memristors exhibit fast threshold switching behaviors, making them suitable for spike generators in neuromorphic computing and stochastic clock generators in security devices. In these applications, a high output spike amplitude is necessary for threshold level control and accurate signal detection. Here, we propose a materialwise solution to obtain the high amplitude spikes by inserting Au nanodots into the NbOx device. The Au nanodots enable increasing the threshold voltage by modulating the oxygen contents at the electrode-oxide interface, providing a higher ON current compared to nanodot-free NbOx devices. Also, the reduction of the local switching region volume decreases the thermal capacitance of the system, allowing the maximum spike amplitude generation. Consequently, the Au nanodot incorporation increases the spike amplitude of the NbOx device by 6 times, without any additional external circuit elements. The results are systematically supported by both a numerical model and a finite-element-method-based multiphysics model.
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Affiliation(s)
- Woojoon Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Gwangmin Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jae Hyun In
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hakseung Rhee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hanchan Song
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Juseong Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Alba Martinez
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Kyung Min Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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6
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Rajan ST, Das M, Arockiarajan A. Biocompatibility and corrosion evaluation of niobium oxide coated AZ31B alloy for biodegradable implants. Colloids Surf B Biointerfaces 2022; 212:112342. [PMID: 35085937 DOI: 10.1016/j.colsurfb.2022.112342] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/13/2022] [Accepted: 01/16/2022] [Indexed: 12/13/2022]
Abstract
Biodegradable magnesium (Mg) based implants have considerable interest in the biomedical field as their use nullifies the necessity for implant removal surgery and avoids the long-standing adverse reaction of permanent bioimplants. The degradation resistance and biocompatibility of the Mg alloys can be improved by coating them with a suitable thin film. Here, thin films of niobium and niobium oxide were developed on the AZ31B Mg alloy by sputtering technique and their biocompatibility and corrosion resistance was examined. X-ray diffraction (XRD) and Transmission electron microscope (TEM) techniques confirmed the crystallinity of the thin films. Subsequently, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques were employed to evaluate the morphology and chemical composition of the thin film surfaces, respectively. Thin-film coated Mg alloys revealed good corrosion resistance compared to their uncoated bare counterparts in simulated body fluid (SBF). The contact angle study was performed on the coated specimens to investigate their wettability which revealed their hydrophobic character. The cell viability studies on thin-film coated specimens exhibited significant cell proliferation, and cell morphological studies showed good cell attachment and growth. The in vitro MTT assay on mouse osteoblast precursor cells (MC3T3-E1) indicated that the Nb-based coatings are cytocompatible and promote cell proliferation.
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Affiliation(s)
- S Thanka Rajan
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600 036, India.
| | - Mitun Das
- Bioceramics and Coating Division, CSIR-Central Glass & Ceramic Research Institute, Kolkata 700032, India
| | - A Arockiarajan
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai 600 036, India; Ceramic Technology Group -Center of Excellence in Materials and Manufacturing Futuristic Mobility, Indian Institute of Technology Madras (IIT Madras), Chennai 600 036, India.
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7
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Ouyang W, Zhou Y, Fei X, Bai Y, Wang H, Wu Z. Simultaneous removal of NO and dichloromethane (CH 2Cl 2) over Nb-loaded cerium nanotubes catalyst. J Environ Sci (China) 2022; 111:175-184. [PMID: 34949347 DOI: 10.1016/j.jes.2021.03.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 06/14/2023]
Abstract
Herein, a series of niobium oxide supported cerium nanotubes (CeNTs) catalysts with different loading amount of Nb2O5 (0-10 wt.%) were prepared and used for selective catalytic reduction of NOx with NH3 (NH3-SCR) in the presence of CH2Cl2. Commercial V2O5-WO3-TiO2 catalyst was also prepared for comparison. The physcial properties and chemical properties of the Nb2O5 loaded cerium nanotubes catalysts were investigated by X-ray diffractometer, Transmission electron microscope, Brunauer-Emmett-Teller specific surface area, H2-temperature programmed reduction, NH3-temperature programmed desorption and X-ray photoelectron spectroscopy. The experiment results showed that the loading amount of Nb2O5 had a significant effect on the catalytic performance of the catalysts. 10 wt.% Nb-CeNTs catalyst presented the best NH3-SCR performance and degradation efficiency of CH2Cl2 among the prepared catalysts, due to its superior redox capability, abundant surface oxygen species and acid sites, the interaction between Nb and Ce, higher ratio of Nb4+/(Nb5++ Nb4+) and Ce3+/(Ce3+ + Ce4+), as well as the special tubular structure of cerium nanotube. This study may provide a practical approach for the design and synthesis of SCR catalysts for the simultaneously removal NOx and chlorinated volatile organic compounds (CVOCs) emitted from the stationary industrial sources.
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Affiliation(s)
- Weilong Ouyang
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Engineering Research Center of Industrial Boiler and Furnace Flue Gas Pollution Control, Hangzhou 310058, China
| | - Yi Zhou
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Engineering Research Center of Industrial Boiler and Furnace Flue Gas Pollution Control, Hangzhou 310058, China
| | - Xiaoqi Fei
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Engineering Research Center of Industrial Boiler and Furnace Flue Gas Pollution Control, Hangzhou 310058, China
| | - Yarong Bai
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Engineering Research Center of Industrial Boiler and Furnace Flue Gas Pollution Control, Hangzhou 310058, China
| | - Haiqiang Wang
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Engineering Research Center of Industrial Boiler and Furnace Flue Gas Pollution Control, Hangzhou 310058, China.
| | - Zhongbiao Wu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resources Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Engineering Research Center of Industrial Boiler and Furnace Flue Gas Pollution Control, Hangzhou 310058, China
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8
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Dai YM, Li YY, Chen BY, Chen CC. One-pot synthesis of acid-base bifunctional catalysts for biodiesel production. J Environ Manage 2021; 299:113592. [PMID: 34479149 DOI: 10.1016/j.jenvman.2021.113592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 08/15/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Acid-base bifunctional heterogeneous solid catalysts, known as the active site with base-acid properties, exhibited relatively good performance on the transesterification for soybean oil for green fuel production. We investigated the use of niobium and three alkali metal oxides (Li, Na, and K) as MyNbOX (M = Li, Na, K) composite as acid-base catalysts for biodiesel production. MyNbOX catalysts were prepared using a simple solid-state reaction, mixing, and grinding niobium dioxide with alkali metal carbonates calcined at 800 °C in air for 4 h. XRD, BET, FE-SEM, TEM and TPD techniques were employed for catalysts characterization. The highest biodiesel yield (98.08%) was achieved under the transesterification condition of 65 °C, 6 h, 24 methanol/oil molar ratio and 2 wt% of LiNbO3 as the catalyst. The results showed that LiNbO3 could be efficiently reused at least 10 cycles with an insignificant reduction in the biodiesel yield. The physicochemical properties of the biodiesel were further studied and compared with the ASTM and the EN biodiesel specifications. The results showed that the properties of the biodiesel produced complied with the international standard specifications.
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Affiliation(s)
- Yong-Ming Dai
- Department of Chemical and Materials Engineering, National Chin-Yi University of Technology, Taichung, 411, Taiwan
| | - Yan-Yun Li
- Department of Science Education and Application, National Taichung University of Education, Taichung, 403, Taiwan
| | - Bing Yi Chen
- Department of Science Education and Application, National Taichung University of Education, Taichung, 403, Taiwan
| | - Chiing-Chang Chen
- Department of Science Education and Application, National Taichung University of Education, Taichung, 403, Taiwan.
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Dong Q, Chen Z, Zhao B, Zhang Y, Lu Z, Wang X, Li J, Chen W. In situ fabrication of niobium pentoxide/graphitic carbon nitride type-II heterojunctions for enhanced photocatalytic hydrogen evolution reaction. J Colloid Interface Sci 2021; 608:1951-1959. [PMID: 34749145 DOI: 10.1016/j.jcis.2021.10.161] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/17/2022]
Abstract
The effective conversion of sunlight into H2 by photocatalytic water splitting has emerged as the most promising strategy to alleviate the energy crisis. In this work, niobium pentoxide (Nb2O5)/graphitic carbon nitride (g-C3N4) type-II heterojunctions with high photocatalytic H2 evolution rate under both visible and simulated solar light are fabricated via a novel approach involving in situ 'hydrolysis/calcination' loading of Nb2O5 nanoparticles on the g-C3N4 surface. After the optimisation, the Nb2O5/g-C3N4 heterojunctions with 5 wt% Nb2O5 content delivers high H2 evolution rates of 2.07 ± 0.03 and 6.77 ± 0.12 mmol g-1 h-1 under visible and simulated solar light exposure, respectively, which are 4.1 and 4.2 times superior to those of pure g-C3N4. According to the subsequent characterisations, the effective Nb2O5/g-C3N4 heterojunction offers sufficient contact interface, which is favourable for the efficient separation of photogenerated charges. In addition, the Nb2O5/g-C3N4 heterojunction possesses a large surface area, which contributes to the interfacial contact between photocatalyst and water. This work provides insights into the synthesis of novel g-C3N4-based hetero-photocatalysts with strong solar energy conversion capabilities.
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Affiliation(s)
- Qian Dong
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Zhiwu Chen
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Bo Zhao
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Yizeng Zhang
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Zhenya Lu
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Xin Wang
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Jinliang Li
- Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong 510632, China.
| | - Wei Chen
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
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10
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Zhu L, Zhong Z, Xue J, Xu Y, Wang C, Wang L. NH 3-SCR performance and the resistance to SO 2 for Nb doped vanadium based catalyst at low temperatures. J Environ Sci (China) 2018; 65:306-316. [PMID: 29548402 DOI: 10.1016/j.jes.2017.06.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 05/26/2017] [Accepted: 06/27/2017] [Indexed: 06/08/2023]
Abstract
Niobium oxide as the promoter was doped in the V/WTi catalyst for the selective catalytic reduction (SCR) of NO. The results showed that the addition of Nb2O5 could improve the SCR activity at low temperatures and the 6wt.% additive was an appropriate dosage. The enhanced reaction activity of adsorbed ammonia species and the improved dispersion of vanadium oxide might be the reasons for the elevation of SCR activity at low temperatures. The resistances to SO2 of 3V6Nb/WTi catalyst at different temperatures were investigated. FTIR spectrum and TG-FTIR result indicated that the deposition of ammonium sulfate species was the main deactivation reason at low temperatures, which still exhibited the reactivity with NO above 200°C on the catalyst surface. There was a synergistic effect among NH3, H2O and SO2 that NH3 and H2O both accelerated the catalyst deactivation in the presence of SO2 at 175°C. The thermal treatment at 400°C could regenerate the deactivated catalyst and get SCR activity recovered. The particle and monolith catalysts both kept stable NOx conversion at 225°C with high concentration of H2O and SO2 during the long time tests.
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Affiliation(s)
- Lin Zhu
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
| | - Zhaoping Zhong
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China.
| | - Jianming Xue
- Guodian Science and Technology Research Institute, Nanjing 210031, China
| | - Yueyang Xu
- Guodian Science and Technology Research Institute, Nanjing 210031, China
| | - Chunhua Wang
- College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Lixia Wang
- Key Laboratory of Energy Thermal Conversion and Control, Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China
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11
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Pauline SA, Rajendran N. Effect of Sr on the bioactivity and corrosion resistance of nanoporous niobium oxide coating for orthopaedic applications. Mater Sci Eng C Mater Biol Appl 2014. [PMID: 24433904 DOI: 10.1016/j.apsusc.2013.11.112] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
In this study, strontium incorporated Nb2O5 was synthesized in two different proportions by sol-gel methodology and was deposited on 316L SS by spin coating method. The synthesis conditions were optimized to obtain a nanoporous morphology. The prepared Sr-incorporated Nb2O5 coatings were uniform, smooth and well adherent on to the substrate 316L SS. The coatings were characterized by attenuated total reflectance-infrared spectroscopy (ATR-IR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and transmission electron microscopy (TEM) and the formation of Sr-incorporated Nb2O5 coatings with nanoporous morphology was confirmed. Static water contact angle measurements showed an enhancement in the wettability of the obtained coatings. In vitro bioactivity test of the coated substrates showed that 0.05M Sr-incorporated Nb2O5 coating had better bioactivity compared to 0.1M Sr-incorporated coating. Solution analysis studies confirmed the controlled release of Sr ions from the coating, which aid and enhance hydroxyapatite (HAp) growth. Electrochemical studies confirmed that the coatings provided excellent corrosion protection to the base material as increased charge transfer resistance and decreased double layer capacitance was observed for the coated substrates.
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Affiliation(s)
- S Anne Pauline
- Department of Chemistry, Anna University, Chennai 600025, India
| | - N Rajendran
- Department of Chemistry, Anna University, Chennai 600025, India.
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