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Tee SY, Kong J, Koh JJ, Teng CP, Wang X, Wang X, Teo SL, Thitsartarn W, Han MY, Seh ZW. Structurally and surficially activated TiO 2 nanomaterials for photochemical reactions. NANOSCALE 2024; 16:18165-18212. [PMID: 39268929 DOI: 10.1039/d4nr02342k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/15/2024]
Abstract
Renewable fuels and environmental remediation are of paramount importance in today's world due to escalating concerns about climate change, pollution, and the finite nature of fossil fuels. Transitioning to sustainable energy sources and addressing environmental pollution has become an urgent necessity. Photocatalysis, particularly harnessing solar energy to drive chemical reactions for environmental remediation and clean fuel production, holds significant promise among emerging technologies. As a benchmark semiconductor in photocatalysis, TiO2 photocatalyst offers an excellent solution for environmental remediation and serves as a key tool in energy conversion and chemical synthesis. Despite its status as the default photocatalyst, TiO2 suffers from drawbacks such as a high recombination rate of charge carriers, low electrical conductivity, and limited absorption in the visible light spectrum. This review provides an in-depth exploration of the fundamental principles of photocatalytic reactions and presents recent advancements in the development of TiO2 photocatalysts. It specifically focuses on strategic approaches aimed at enhancing the performance of TiO2 photocatalysts, including improving visible light absorption for efficient solar energy harvesting, enhancing charge separation and transportation efficiency, and ensuring stability for robust photocatalysis. Additionally, the review delves into the application of photodegradation and photocatalysis, particularly in critical processes such as water splitting, carbon dioxide reduction, nitrogen fixation, hydrogen peroxide generation, and alcohol oxidation. It also highlights the novel use of TiO2 in plastic polymerization and degradation, showcasing its potential for converting plastic waste into valuable chemicals and fuels, thereby offering sustainable waste management solutions. By addressing these essential areas, the review offers valuable insights into the potential of TiO2 photocatalysis for addressing pressing environmental and energy challenges. Furthermore, the review encompasses the application of TiO2 photochromic systems, expanding its scope to include other innovative research and applications. Finally, it addresses the underlying challenges and provides perspectives on the future development of TiO2 photocatalysts. Through addressing these issues and implementing innovative strategies, TiO2 photocatalysis can continue to evolve and play a pivotal role in sustainable energy and environmental applications.
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Affiliation(s)
- Si Yin Tee
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Junhua Kong
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Justin Junqiang Koh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Choon Peng Teng
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Xizu Wang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Xiaobai Wang
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Siew Lang Teo
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Warintorn Thitsartarn
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Ming-Yong Han
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, China.
| | - Zhi Wei Seh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
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Li G, Zhang Y, Wu P, Shen K, Zhang S, Ding S. Improved activity and significant SO 2 tolerance of Sb-Pd-V oxides on N-doped TiO 2 for CB/NO x synergistic degradation. CHEMOSPHERE 2023; 329:138613. [PMID: 37030352 DOI: 10.1016/j.chemosphere.2023.138613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 02/10/2023] [Accepted: 04/03/2023] [Indexed: 05/03/2023]
Abstract
The synergistic degradation of VOCs and NOx that were emitted from the incineration of municipal and medical wastes by a single catalyst is challenging, due to the poor activity at low temperatures, and the SO2 poisoning on the active sites. Herein, N-doped TiO2 (N-TiO2) was used as the support for designing a highly efficient and stable catalyst system for CB/NOx synergistic degradation even in the presence of SO2. The prepared SbPdV/N-TiO2 catalyst, which presented excellent activity and tolerance to SO2 in the CBCO + SCR process, was investigated by a series of characterizations (such as XRD, TPD, XPS, H2-TPR and so on) as well as DFT calculations. The electronic structure of the catalyst was effectively modulated after N doping, resulting in effective charge flow between the catalyst surface and gas molecules. More importantly, the adsorption and deposition of sulfur species and reaction transient intermediates on active centers were restrained, while a new N adsorption center for NOx was provided. Abundant adsorption centers and superior redox properties ensured smooth CB/NOx synergistic degradation. The removal of CB mainly follows the L-H mechanism, while NOx elimination follows both E-R and L-H mechanisms. As a result, N doping provides a new approach to develop more advanced anti-SO2 poisoning CB/NOx synergistic catalytic removal systems for extensive applications.
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Affiliation(s)
- Guobo Li
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Yaping Zhang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Peng Wu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Kai Shen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China
| | - Shule Zhang
- School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, PR China
| | - Shipeng Ding
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, Jiangsu, PR China.
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El Sharkawy HM, Shawky AM, Elshypany R, Selim H. Efficient photocatalytic degradation of organic pollutants over TiO 2 nanoparticles modified with nitrogen and MoS 2 under visible light irradiation. Sci Rep 2023; 13:8845. [PMID: 37258591 DOI: 10.1038/s41598-023-35265-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/15/2023] [Indexed: 06/02/2023] Open
Abstract
Investigate the use of visible light to improve photocatalytic degradation of organic pollutants in wastewater. Nitrogen-doped titania and molybdenum sulfide nanocomposites (NTM NCs) with different weight ratios of MoS2 (1, 2, and 3 wt.%) synthesized by a solid state method applied to the photodegradation of methylene blue(MB) under visible light irradiation. The synthesized NTM composites were characterized by SEM, TEM, XRD, FT-IR, UV-Vis, DRS and PL spectroscopy. The results showed enhanced activity of NTM hybrid nanocrystals in oxidizing MB in water under visible light irradiation compared to pure TiO2. The photocatalytic performance of NTM samples increased with MoS2 content. The results show that the photodegradation efficiency of the TiO2 compound improved from 13 to 82% in the presence of N-TiO2 and to 99% in the presence of MoS2 containing N-TiO2, which is 7.61 times higher than that of TiO2. Optical characterization results show enhanced nanocomposite absorption in the visible region with long lifetimes between e/h+ at optimal N-TiO2/MoS2 (NTM2) ratio. Reusable experiments indicated that the prepared NTM NCs photocatalysts were stable during MB photodegradation and had practical applications for environmental remediation.
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Affiliation(s)
- Heba M El Sharkawy
- Department of Analysis and Evaluation, Egyptian Petroleum Research Institute, Nasr City, 11727, Cairo, Egypt
| | - Amira M Shawky
- Sanitary and Environmental Institute (SEI), Housing and Building National Research Center (HBRC), Giza, 1770, Egypt
| | - Rania Elshypany
- Department of Analysis and Evaluation, Egyptian Petroleum Research Institute, Nasr City, 11727, Cairo, Egypt
| | - Hanaa Selim
- Department of Analysis and Evaluation, Egyptian Petroleum Research Institute, Nasr City, 11727, Cairo, Egypt.
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Wang H, Dong M, Shao B, Chi Y, Wang C, Lv S, Duan R, Wu B, Yang X. Efficient Photodegradation of Rhodamine B by Fiber-like Nitrogen-Doped TiO 2/Ni(OH) 2 Nanocomposite under Visible Light Irradiation. MICROMACHINES 2023; 14:870. [PMID: 37421103 DOI: 10.3390/mi14040870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 07/09/2023]
Abstract
N-TiO2/Ni(OH)2 nanofiber was successfully prepared by combining the electrospinning and solvothermal method. It has been found that under visible light irradiation, the as-obtained nanofiber exhibits excellent activity for the photodegradation of rhodamine B, and the average degradation rate reaches 3.1%/min-1. Further insight investigations reveal that such a high activity was mainly due to the heterostructure-induced increase in the charge transfer rate and separation efficiency.
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Affiliation(s)
- Huan Wang
- Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
- Department of Materials Science, Jilin Jianzhu University, Changchun 130118, China
| | - Mingxuan Dong
- Department of Materials Science, Jilin Jianzhu University, Changchun 130118, China
| | - Baorui Shao
- Department of Materials Science, Jilin Jianzhu University, Changchun 130118, China
| | - Yaodan Chi
- Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Chao Wang
- Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Sa Lv
- Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Ran Duan
- Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Boqi Wu
- Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
| | - Xiaotian Yang
- Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education, Jilin Jianzhu University, Changchun 130118, China
- Department of Chemistry, Jilin Normal University, Siping 136000, China
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Kwon J, Choi K, Schreck M, Liu T, Tervoort E, Niederberger M. Gas-Phase Nitrogen Doping of Monolithic TiO 2 Nanoparticle-Based Aerogels for Efficient Visible Light-Driven Photocatalytic H 2 Production. ACS APPLIED MATERIALS & INTERFACES 2021; 13:53691-53701. [PMID: 34730952 DOI: 10.1021/acsami.1c12579] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The development of visible light-active photocatalysts is essential for increasing the conversion efficiency of solar energy into hydrogen (H2). Here, we present a facile method for nitrogen doping of monolithic titanium dioxide (TiO2) nanoparticle-based aerogels to activate them for visible light. Plasma-enhanced chemical vapor deposition at low temperature enables efficient incorporation of nitrogen into preformed TiO2 aerogels without compromising their advantageous intrinsic characteristics such as large surface area, extensive porosity, and nanoscale properties of the semiconducting building blocks. By balancing the dopant concentration and the defects, the nitridation improves optical absorption and charge separation efficiency. The nitrogen-doped TiO2 nanoparticle-based aerogels loaded with palladium (Pd) nanoparticles show a significant enhancement in visible light-driven photocatalytic H2 production (3.1 mmol h-1 g-1) with excellent stability over 5 days. With this method, we introduce a powerful tool to tune the properties of nanoparticle-based aerogels after synthesis for a specific application, as exemplified by visible light-driven H2 production.
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Affiliation(s)
- Junggou Kwon
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland
| | - Kyoungjun Choi
- Nanoscience for Energy Technology and Sustainability, Department of Mechanical and Process Engineering, ETH Zurich, Tannenstrasse 3, Zürich 8092, Switzerland
| | - Murielle Schreck
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland
| | - Tian Liu
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland
| | - Elena Tervoort
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland
| | - Markus Niederberger
- Laboratory for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zürich 8093, Switzerland
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Ashfaq A, Ikram M, Haider A, Ul-Hamid A, Shahzadi I, Haider J. Nitrogen and Carbon Nitride-Doped TiO 2 for Multiple Catalysis and Its Antimicrobial Activity. NANOSCALE RESEARCH LETTERS 2021; 16:119. [PMID: 34312737 PMCID: PMC8313641 DOI: 10.1186/s11671-021-03573-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 07/13/2021] [Indexed: 05/21/2023]
Abstract
Nitrogen (N) and carbon nitride (C3N4)-doped TiO2 nanostructures were prepared using co-precipitation route. Fixed amount of N and various concentrations (0.1, 0.2, 0.3 wt%) of C3N4 were doped in TiO2 lattice. Through multiple techniques, structural, chemical, optical and morphological properties of samples were thoroughly investigated. XRD results verified anatase TiO2 presence along the substitutional doping of N, while higher degree of crystallinity as well as increased crystallite size were noticed after doping. HR-TEM study revealed formation of nanostructures incorporated on two dimensional (2D) C3N4 nanosheet surface. Elemental composition was checked out using EDS technique which confirmed the presence of dopant in product. Optical characteristics were evaluated with UV-vis spectroscopy which depicted representative redshift in absorption spectra resulted in a reduction in bandgap energy in N/C3N4-doped TiO2 samples. The formation of Ti-O-Ti bonds and different molecular vibrations were disclosed by FTIR. Trap sites and charge carrier's migration in the materials were evaluated with PL spectroscopy. Multiple catalytic activities (photo, sono and photo-sono) were undertaken to evaluate the dye degradation performance of prepared specimen against methylene blue and ciprofloxacin. Further, antimicrobial activity was analyzed against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria.
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Affiliation(s)
- Atif Ashfaq
- Solar Cell Application Research Lab, Department of Physics, Government College University Lahore, Lahore, Punjab, 54000, Pakistan
| | - Muhammad Ikram
- Solar Cell Application Research Lab, Department of Physics, Government College University Lahore, Lahore, Punjab, 54000, Pakistan.
| | - Ali Haider
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, Lahore, Punjab, 54000, Pakistan
| | - Anwar Ul-Hamid
- Core Research Facilities, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.
| | - Iram Shahzadi
- Punjab University College of Pharmacy, University of the Punjab, Lahore, 54000, Pakistan
| | - Junaid Haider
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
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7
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Abstract
This article presents an overview of the reports on the doping of TiO2 with carbon, nitrogen, and sulfur, including single, co-, and tri-doping. A comparison of the properties of the photocatalysts synthesized from various precursors of TiO2 and C, N, or S dopants is summarized. Selected methods of synthesis of the non-metal doped TiO2 are also described. Furthermore, the influence of the preparation conditions on the doping mode (interstitial or substitutional) with reference to various types of the modified TiO2 is summarized. The mechanisms of photocatalysis for the different modes of the non-metal doping are also discussed. Moreover, selected applications of the non-metal doped TiO2 photocatalysts are shown, including the removal of organic compounds from water/wastewater, air purification, production of hydrogen, lithium storage, inactivation of bacteria, or carbon dioxide reduction.
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Divyasri YV, Lakshmana Reddy N, Lee K, Sakar M, Navakoteswara Rao V, Venkatramu V, Shankar MV, Gangi Reddy NC. Optimization of N doping in TiO 2 nanotubes for the enhanced solar light mediated photocatalytic H 2 production and dye degradation. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 269:116170. [PMID: 33321309 DOI: 10.1016/j.envpol.2020.116170] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 11/01/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Herein, we report the optimization of nitrogen (N) doping in TiO2 nanotubes to achieve the enhanced photocatalytic efficiencies in degradation of dye and H2 gas evolution under solar light exposure. TiO2 nanotubes have been produced via hydrothermal process and N doping has been tuned by varying the concentration of urea, being the source for N, by solid-state dispersion process. The structural analysis using XRD showed the characteristic occupancy of N into the structure of TiO2 and the XPS studies showed the existence of Ti-N-Ti network in the N-doped TiO2 nanotubes. The obtained TEM images showed the formation of 1D tube-like structure of TiO2. Diffuse reflectance UV-Vis absorption spectra demonstrated that the N-doped TiO2 nanotubes can efficiently absorb the photons of UV-Vis light of the solar light. The optimized N-doped TiO2 nanotubes (TiO2 nanotubes vs urea @ 1:1 ratio) showed the highest degradation efficiency over methyl orange dye (∼91% in 90 min) and showed the highest rate of H2 evolution (∼19,848 μmol h-1.g-1) under solar light irradiation. Further, the recyclability studies indicated the excellent stability of the photocatalyst for the durable use in both the photocatalytic processes. The observed efficiency was ascribed to the optimized doping of N-atoms into the lattices of TiO2, which enhanced the optical properties by forming new energy levels of N atoms near the valence band maximum of TiO2, thereby increased the overall charge separation and recombination resistance in the system. The improved reusability of photocatalyst is attributed to the doping-induced structural stability in N-doped TiO2. From the observed results, it has been recognized that the established strategy could be promising for synthesizing N-doped TiO2 nanotubes with favorable structural, optical and photocatalytic properties towards dye degradation and hydrogen production applications.
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Affiliation(s)
| | - Nagappagari Lakshmana Reddy
- Department of Energy Chemical Engineering, School of Nano & Materials Science and Engineering, Kyungpook National University, 2559 Gyeongsang-daero, 37224, Sangju, Republic of Korea
| | - Kiyoung Lee
- Department of Energy Chemical Engineering, School of Nano & Materials Science and Engineering, Kyungpook National University, 2559 Gyeongsang-daero, 37224, Sangju, Republic of Korea
| | - M Sakar
- Centre for Nano and Material Sciences, Jain University, Bangalore, 562 112, Karnataka, India
| | - Vempuluru Navakoteswara Rao
- Nanocatalysis and Solar Fuels Research Laboratory, Department of Materials Science & Nanotechnology, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India
| | - Vemula Venkatramu
- Department of Physics, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India; Department of Physics, Krishna University Dr. MRAR PG Centre, Nuzvid, 521 201, Andhra Pradesh, India
| | - Muthukonda Venkatakrishnan Shankar
- Nanocatalysis and Solar Fuels Research Laboratory, Department of Materials Science & Nanotechnology, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India
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Kim N, Raj MR, Lee G. Nitrogen-doped TiO 2(B) nanobelts enabling enhancement of electronic conductivity and efficiency of lithium-ion storage. NANOTECHNOLOGY 2020; 31:415401. [PMID: 32580178 DOI: 10.1088/1361-6528/ab9fb6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
To enhance the intrinsic electrical conductivities of TiO2(B) nanobelts, nitrogen(N)-doped TiO2(B) nanobelts (N-TNB) were prepared in this study by a facile and cost-effective hydrothermal method using urea as the nitrogen source with TiO2 (P25) nanoparticles. x-ray photoelectron spectroscopy confirmed that the N-atoms preferentially occupied up to ∼0.516 atom% in the interstitial sites of the N-TNB and the maximum concentration of substituted-N bonds in the N-TNB was ∼0.154 atom%, thereby the total concentration of doped nitrogen elements of ∼0.67 atom% improved the high intrinsic electrical conductivity and ionic diffusivity of the TiO2(B) nanobelts. The as-prepared N-TNB electrode delivered the highest specific capacity of 133.9 mAh g-1 in the first cycle, with an exceptional cyclic capacity retention at an ultrafast current rate of 1000 mA g-1; this is not less than 51% after 500 cycles and represents an excellent rate capability of ∼37 mAh g-1 at an ultra-high rate of 40 C. These values are among the best ever reported on comparison of the delivered highest discharge capacity of N-TNB at 1000 mA g-1 and high-rate capabilities of its Li+ ion storage with the literature data for N-TNB (∼231.5 mAh g-1 at a very low current density of 16.75 mA g-1, ∼0.1 C) of similar materials used in sodium-ion batteries. This implies the potential feasibility of these N-TNB as high-capacity anode materials for next-generation, high-energy-density, electrochemical energy-storage devices.
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Affiliation(s)
- Nangyeong Kim
- Advanced Energy Materials Design Lab, School of Chemical Engineering, Yeungnam University, Gyeongsan-Si 38541 Republic of Korea
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Development and Validation of a LC-MS/MS Method for Determination of Multi-Class Antibiotic Residues in Aquaculture and River Waters, and Photocatalytic Degradation of Antibiotics by TiO2 Nanomaterials. Catalysts 2020. [DOI: 10.3390/catal10030356] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This study presents a multi-residue method for simultaneous qualitative and quantitative analysis of eight antibiotics from some common classes, including beta-lactam, tetracyclines, lincosamides, glycopeptides, and sulfonamides in 39 aquaculture and river water samples from the Mekong Delta (Vietnam) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). As a result, doxycycline (DXC), oxytetracycline (OTC), lincomycin (LCM), sulfamethoxazole (SMX), and sulfamethazine (SMZ) were detected with high frequency over 65% and an average concentration of 22.6–76.8 ng·mL−1. The result suggests that antibiotic residues in the aquaculture and river waters are considered as an emerging environmental problem of the region. To address this issue, we fabricated the well-defined TiO2 nanotube arrays (TNAs) and nanowires on nanotube arrays (TNWs/TNAs) using the anodization method. The TNAs had an inner tube diameter of ~95 nm and a wall thickness of ~25 nm. Meanwhile, the TNWs/TNAs had a layer of TiO2 nanowires with a length of ~6 µm partially covering the TNAs. In addition, both TNAs and TNWs/TNAs had pure anatase phase TiO2 with (101) and (112) dominant preferred orientations. Moreover, the TNAs and TNWs/TNAs effectively and rapidly degraded the antibiotic residues under UV-VIS irradiation at 120 mW/cm2 and obtained over 95% removal at 20 min. Indeed, the photocatalytic reaction rate constants (k) were in the range of 0.14–0.36 min−1 for TNAs, and 0.15–0.38 min−1 for TNWs/TNAs. Noticeably, the k values of TNWs/TNAs were slightly higher than those of TNAs for LCM, DXC, OTC, SMZ, and SMX that could be attributed to the larger surface area of TNWs/TNAs than TNAs when TNWs/TNAs had an additional ~6μm TNWs top layer.
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Electrochemical Engineering of Nanoporous Materials for Photocatalysis: Fundamentals, Advances, and Perspectives. Catalysts 2019. [DOI: 10.3390/catal9120988] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Photocatalysis comprises a variety of light-driven processes in which solar energy is converted into green chemical energy to drive reactions such as water splitting for hydrogen energy generation, degradation of environmental pollutants, CO2 reduction and NH3 production. Electrochemically engineered nanoporous materials are attractive photocatalyst platforms for a plethora of applications due to their large effective surface area, highly controllable and tuneable light-harvesting capabilities, efficient charge carrier separation and enhanced diffusion of reactive species. Such tailor-made nanoporous substrates with rational chemical and structural designs provide new exciting opportunities to develop advanced optical semiconductor structures capable of performing precise and versatile control over light–matter interactions to harness electromagnetic waves with unprecedented high efficiency and selectivity for photocatalysis. This review introduces fundamental developments and recent advances of electrochemically engineered nanoporous materials and their application as platforms for photocatalysis, with a final prospective outlook about this dynamic field.
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TiO 2 and Au-TiO 2 Nanomaterials for Rapid Photocatalytic Degradation of Antibiotic Residues in Aquaculture Wastewater. MATERIALS 2019; 12:ma12152434. [PMID: 31370138 PMCID: PMC6695739 DOI: 10.3390/ma12152434] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/26/2019] [Accepted: 07/27/2019] [Indexed: 11/17/2022]
Abstract
Antibiotic residues in aquaculture wastewater are considered as an emerging environmental problem, as they are not efficiently removed in wastewater treatment plants. To address this issue, we fabricated TiO2 nanotube arrays (TNAs), TiO2 nanowires on nanotube arrays (TNWs/TNAs), Au nanoparticle (NP)-decorated-TNAs, and TNWs/TNAs, which were applied for assessing the photocatalytic degradation of eight antibiotics, simultaneously. The TNAs and TNWs/TNAs were synthesized by anodization using an aqueous NH4F/ethylene glycol solution. Au NPs were synthesized by chemical reduction method, and used to decorate on TNAs and TNWs/TNAs. All the TiO2 nanostructures exhibited anatase phase and well-defined morphology. The photocatalytic performance of TNAs, TNWs/TNAs, Au-TNAs and Au-TNWs/TNAs was studied by monitoring the degradation of amoxicillin, ampicillin, doxycycline, oxytetracycline, lincomycin, vancomycin, sulfamethazine, and sulfamethoxazole under ultraviolet (UV)-visible (VIS), or VIS illumination by LC-MS/MS method. All the four kinds of nanomaterials degraded the antibiotics effectively and rapidly, in which most antibiotics were removed completely after 20 min treatment. The Au-TNWs/TNAs exhibited the highest photocatalytic activity in degradation of the eight antibiotics. For example, reaction rate constants of Au-TNWs/TNAs for degradation of lincomycin reached 0.26 min−1 and 0.096 min−1 under UV-VIS and VIS irradiation, respectively; and they were even higher for the other antibiotics. The excellent photocatalytic activity of Au-TNWs/TNAs was attributed to the synergistic effects of: (1) The larger surface area of TNWs/TNAs as compared to TNAs, and (2) surface plasmonic effect in Au NPs to enhance the visible light harvesting.
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Lee K, Yoon H, Ahn C, Park J, Jeon S. Strategies to improve the photocatalytic activity of TiO 2: 3D nanostructuring and heterostructuring with graphitic carbon nanomaterials. NANOSCALE 2019; 11:7025-7040. [PMID: 30920558 DOI: 10.1039/c9nr01260e] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
TiO2-based photocatalysis has been considered to be one of the most promising avenues for environmental remediation including water purification. However, several technical issues such as the limited surface area of bulk TiO2, the large band gap of TiO2, and rapid charge recombination still limit the practical application of TiO2 photocatalysts. Therefore, here we focus on two structural design strategies: (i) monolithic three-dimensional (3D) nanostructuring, and (ii) heterostructuring with graphitic carbon nanomaterials. A monolithic 3D nanostructure enables maximal surface area in a given volume and efficient reuse of the photocatalyst without recollection. Heterostructuring with carbon nanomaterials helps achieve maximal utilization of the solar spectrum and charge separation and provides efficient TiO2 photocatalysts. In this review, recent progress on TiO2 photocatalysts toward the abovementioned strategies will be summarized. Further discussion and direction will provide insights into the rational design of highly efficient TiO2 photocatalysts, and help develop advanced photocatalyst models.
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Affiliation(s)
- Kisung Lee
- Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, Advanced Battery Center, KAIST, Daejeon 34141, Republic of Korea.
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