CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Di Pang,Yue Liu,Haiou Song,Duozhe Chen,Weiqing Zhu,Rumeng Liu,Hu Yang,Aimin Li,Shupeng Zhang
A trace Ti 3+ - and N-codoped TiO 2 nanotube array (TiON) anode is fabricated by electrochemical reduction after introducing nitrogen into the TiON. The TiON anode material is characterized by scanning electron microscopy, X-ray diffraction, Raman spectra and X-ray photoelectron spectroscopy. Electrochemical analyses of TiON, including cyclic voltammetry, electrochemical impedance spectroscopy and linear scan voltammetry, are conducted to confirm that the electrochemical performance could be significantly improved by electrochemical reduction and N doping. The achieved TiON anode is applied to the electrocatalytic oxidation of tetracycline (TC) and metronidazole (MNZ). The effect of applied current density, initial solution pH and initial TC/MNZ concentration on the reaction kinetics is systematically evaluated to obtain the optimal conditions. The degradation processes follow an apparent first-order kinetic model in all conditions. After 240 min of reaction time, the TC removal efficiency, chemical oxygen demand (COD) removal rate and total organic carbon (TOC) removal rate are >99%, 92.86% and 74.98%, respectively. The MNZ removal efficiency, COD and TOC removal rate achieved are >99%, 93.03% and 79.30%, respectively, after 240 min of degradation. The excellent removal efficiency of TC and MNZ indicates that this TiON anode is a promising material in the practical application of removing antibiotics from water.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Yangfan Zhang,Yao Li,Han Yu,Kai Yu,Hongbing Yu
Defect sites on oxide semiconductors play a crucial role in promoting photocatalytiperformance and modulating the bandgap structure of photocatalysts. However, the role of interfacial coordinatively unsaturated defect sites between metal and oxide in photocatalysis is still under debate. So, we designed an experiment to probe the role of interfacial coordinatively unsaturated defect sites. In this work, a series of Ti/TiO2 photocatalysts with varying concentrations of interfacial Ti3+ sites were prepared through an epitaxial growth method under hydrothermal conditions. Through experimental and computational investigations, the roles of interfacial defect sites were discussed in detail. On the one hand, the interfacial coordinatively unsaturated Ti3+ sites could act as visible-light-responsive sites in photocatalytic reactions due to the overlap and hybridization of multiple electronic orbitals. On the other hand, the Ti/TiO2 interface exhibited a certain degree of metallic character near the Fermi level because of the partial delocalization and redistribution of electrons, facilitating the charge migration and separation across the metal-oxide interface. Consequently, the obtained Ti/TiO2 catalysts showed notably enhanced charge transfer efficiency and visible light photocatalytic activity compared to their pristine counterparts. This work may provide a new perspective to interfacial defect engineering in classic metal/oxide heterojunction photocatalysts and figure a more precise direction to synthesize higher effective photocatalysts for environmental governance.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Caifeng Zhao,Yahui Yang,Lin Luo,Sai Shao,Yiji Zhou,Ying Shao,Faqi Zhan,Jian Yang,Yaoyu Zhou
Oxygen vacancies and Ti 3+ defects in anatase TiO 2 have attracted great attention to address the insufficient optical absorption and photoinduced charge-carrier separation in photocatalysis . In this study, we demonstrate a superficial and innovative approach for synthesizing anatase TiO 2 nanoparticles with abundant oxygen vacancies via γ-ray irradiation reduction at room temperature. X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) confirm that oxygen vacancies and Ti 3+ defects can be quantitatively and extensively obtained by merely regulating the irradiation dosage. Photoelectrochemical measurements suggest that oxygen vacancies and Ti 3+ defects promoted the separation of electron-hole pairs and then enhanced the photocatalytic degradation performance for organic pollutant. In comparison with TiO 2 (no irradiation), the sample (49.5 kGy irradiation) exhibited a 20.0-fold enhancement in visible-light decomposition of phenol. In addition, the results of scavenge experiments and mechanism analysis revealed that O 2 − are the dominant active species. The excited electrons generated at the conduction band and oxygen vacancy level of TiO 2−x -49.5 conspicuously contributes to generate much more ·O 2 − species. This novel study shows at room temperature, the γ-ray approach of irradiation leads to faster formation and quantification of oxygen vacancies in the semiconductor materials .
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 55
·期 2
·701-712
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IF 3.442
Yang Wangyang,Shen Honglie,Min Huihua,Ge Jiawei
In recent years, Ti 3+ self-doped TiO 2 (B-TiO 2 ) exhibits great potential as a photocatalyst. In this work, Ti vapor-assisted annealing is first demonstrated for Ti 3+ doping and improving the visible absorption of TiO 2 . TEM results exhibit the formation of disordered layer, indicating the successful fabricating of B-TiO 2 . The absorption increase in TiO 2 caused by Ti vapor annealing reaches nearly 50% in the visible wavelength range. Benefiting from the absorption increase, the photocatalytic performance of TiO 2 after Ti vapor annealing increases by 60–70%. Surface modification of Ag onto B-TiO 2 is also carried out to further improve its optical property. Ag-modified Ti 3+ self-doped TiO 2 (B-TiO 2 @Ag) exhibits great visible photodegradation behavior to RhB. The RhB degradation rate reaches 97.76% after 60 min of visible light irradiation. Electrochemical performance tests demonstrate that as-prepared TiO 2 @Ag has lower resistance than W-TiO 2 . The results indicate that B-TiO 2 @Ag has great potential in solar photocatalytic degradation of pollutant.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
高影响因子
ACS Omega
·
2019
·
IF 2.584
Xiaogang Liu,Guiru Du,Meng Li
Combining the advantages of reactive crystal facets and engineering defects is an encouraging way to address the inherent disadvantages of titanium dioxide (TiO2) nanocrystals. However, revealing the true photoreactivity origin for defective TiO2 with coexposed or predominant exposed anisotropic facets is still highly challenging. Here, the photoreactivity of TiO2 nanocrystals with respectively predominant exposed {001}, {101}, and {100} facets before and after Ti3+ doping under both ultraviolet and visible light was compared systematically. In detail, the photocatalytic H2 production for R-TiO2-001, R-TiO2-101, and R-TiO2-100 increased by a factor of 1.34, 2.65, and 3.39 under UV light and a factor of 8.90, 13.47, and 8.72 under visible light. By contrast, the photocatalytic degradation of methyl orange for R-TiO2-001, R-TiO2-101, and R-TiO2-100 increased by a factor of 3.18, 1.42, and 2.17 under UV light and a factor of 4.03, 2.85, and 1.58 under visible light, respectively. The true photocatalytic activity origin for the obtained photoreduction and photo-oxidation ability is attributed to the exposure of more active sites (under-coordinated 5-fold Ti atoms), the facilitated charge transfer among {001}, {101}, and {100} facets, and the Ti3+ energy state with variable doping levels to extend the visible light response. This work hopefully provides significant insights into the photoreactivity origin of defective TiO2 nanocrystals with anisotropic exposed facets.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
·
IF 2.843
Jiaojiao Jiang,Zipeng Xing,Meng Li,Zhenzi Li,Xiaoyan Wu,Mengqiao Hu,Jiafeng Wan,Nan Wang,Alexey Sergeevich Besov,Wei Zhou
In situ Ti3+/N-codoped 3D urchinlike black TiO2 (b-N-TiO2) is synthesized via hydrothermal treatment with an in situ solid-state chemical reduction method, followed by annealing at 350 °C in argon. The results indicate that N and Ti3+ was codoped into the lattice of anatase TiO2. The prepared b-N-TiO2, with a narrow bandgap of ∼2.43 eV, possesses a three-dimensional (3D) urchinlike nanostructure, which is composed of fiberlike architecture with a length of 200–400 nm and a width of 25 nm. The visible-light-driven photocatalytic degradation rate of Methyl Orange and hydrogen evolution rate for b-N-TiO2 are 95.2% and 178 μmol h–1 g–1, respectively, which are ∼3 and ∼8 times higher than those of pristine TiO2. The excellent photocatalytic activity is mainly attributed to synergistic effect of the N and Ti3+ codoping narrowing the bandgap, and unique 3D urchinlike architecture favors the separation and transport of photogenerated charge carriers and offers more surface-active sites.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2023
·
IF 5.5
Jiayang Zheng,Cheng Liu,Zhiwen Wang,Yingzhang Shi,Yidong Hou,Jinhong Bi,Ling Wu
Ultrathin TiO 2 nanosheets (NST) containing Ti 3+ sites are developed as a photocatalyst that exhibits high degradation efficiencies (98.6%) for the degradation of enrofloxacin (ENR) under visible light. The increment of degradation efficiencies for ENR over NST is mainly due to the increase of Ti 3+ and oxygen vacancies (OVs). Ti 3+ sites on the surface of NST can be associated with ENR molecules through the formation of surface coordination species -COO∙∙∙Ti- intermediates, resulting in the activation of ENR. OVs on NST can adsorb and activate more O 2 molecules to accelerate the generation of O 2 - by photogenerated electrons reduction. The photogenerated holes quickly transfer to the surface of the catalyst to directly degrade the activated ENR. Finally, a possible mechanism about the synergistic effect of coordination activation and photocatalysis is proposed over NST at a molecule level. This study highlights the significant role of coordination activation in the photocatalytic degradation of antibiotics.
研究领域:
环境科学
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材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 78
·74376-74383
·
IF 3.289
Maoqin Qiu,Yuan Tian,Zhangxian Chen,Zeheng Yang,Wenming Li,Kai Wang,Lei Wang,Kun Wang,Weixin Zhang
Self-doping by Ti3+ and introducing oxygen vacancies in TiO2 is an important and effective strategy to extend its optical absorption from the UV into the visible region. In this paper, we report the synthesis of a series of Ti3+ self-doped TiO2 nanocrystals via a hydrothermal method using TiCl3 and (NH4)2TiF6 as the source of Ti3+ and Ti4+, respectively. The oxidation of Ti3+ can be inhibited by (NH4)2TiF6 based on Le Chatelier's principle. The samples are characterized by X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance, field-emission scanning electron microscopy and transmission electron microcopy, respectively. The results indicate that Ti3+ is localized in the bulk of the as-prepared TiO2 nanocrystals, rather than on the surface. In comparison with pristine TiO2, the Ti3+ self-doped TiO2 nanocrystals exhibit an enhanced photocatalytic activity of 86.3% towards the photodegradation of methylene blue solution under simulated solar light irradiation and 99% under natural solar irradiation. It is found that the molar ratio of Ti4+/Ti3+ used during the synthesis has significant effects on the photocatalytic activity of Ti3+ self-doped TiO2 photocatalysts, since the electronic structures of the resulting Ti3+ self-doped TiO2 nanocrystals can be finely tuned by changing the ratios. The significantly enhanced photocatalytic activity should be due to the self-doping of Ti3+ in TiO2 nanocrystals, which not only increases the optical absorption in the visible light region, but also helps to spatially separate the photogenerated charge carriers.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Yuxuan Wang,Chenhui Qiu,Yujing Xie,Lei Wang,Jing Ding,Jinfeng Zhang,Hui Wan,Guofeng Guan
Using perovskite photocatalytic reduction of CO2 and H2O to produce hydrocarbon fuels offers an attractive method to solve the energy crisis and the greenhouse effect. Bi4Ti3O12 (BTO) has received much attention in the field of photocatalysis due to its unique layered structure, but it still faces many challenges such as weak photoresponse and severe photogenerated carrier recombination. In this paper, Bi4Ti3O12 nanosheets with different concentrations of surface oxygen vacancies (VO) and Ti3+ defect were prepared by the molten salt method and NaBH4 high-temperature reduction method (HBTO). Surface defects formed obvious carrier traps on the HBTO surface, reduced the recombination rate of photogenerated electrons and holes, and adjusted the band gap structure (from 3.09 to 2.62 eV), which improved the visible light utilization of HBTO. The decrease of photoinduced carrier recombination rate and the improvement of visible light response significantly enhanced the photocatalytic CO2 reduction activity of HBTO under visible light. The CH3OH yield with the optimized HBTO-4 (NaBH4:Bi4Ti3O12 = 1:5) was 4.90 μmol·g–1·h–1, which was about 3.5 times that of the original BTO. Meanwhile, the band gap structure, electronic density of states (DOS), and work function were calculated by the density functional theory (DFT). This study provided an effective strategy for designing and preparing perovskite photocatalysts rich in surface defects for the efficient conversion of solar energy.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Bo Li,Xuxia Zhang,Xin Yang,Yuhong Xu,Weilong Chun,Qingqing Hao,Jianbo Zhang,Zhuo Li,Huiyong Chen,Xiaoxun Ma
Ti 3+ defective TiO 2 nanoparticles (TiO 2 -NPs) were synthesized through slow hydrolyzation of tetrabutyl titanate and low-temperature annealing, followed by loading on self-pillared pentasil (SPP) zeolite nanosheets to construct a TiO 2 /zeolite hybrid composite by solid-state dispersion. The obtained TiO 2 -NPs/SPP composite exhibited a distinct red-shift in the UV–vis absorption spectrum and a significantly reduced band gap due to the introduced Ti 3+ defects and the consequent oxygen vacancies (V O ), leading to an enhanced visible-light responsivity. The diverse porosity and house-of-cards nanosheet morphology of the SPP support not only promoted the efficient loading and stable immobilization of TiO 2 -NPs nanoparicles through micropore migration and surface adhesion but also endowed the adsorbability to the TiO 2 -NPs/SPP composite. The adsorptive photodegradation of methylene blue (MB) was used to evaluated the photocatalytic performance of TiO 2 -NPs/SPP, and a 95.6 % degradation rate of MB was observed after 3 h illumination with visible-light. The adsorptive effect strongly promoted the accessibility of MB molecules to the active TiO 2 species, leading to a remarkable enhancement in degradation efficiency. Moreover, a superior recyclability embodied in the retention of 96.4 % photocatalytic activity after three regeneration cycles indicated the TiO 2 -NPs/SPP composite to be practical for water pollutant degradation.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Lianying Lu,Guohong Wang,Ziwei Xiong,Zifei Hu,Yuwei Liao,Juan Wang,Jun Li
A heterojunction of plasmonic Ag particles on Ti 3+ -doped macro-/meso-porous TiO 2 framework consisting of parallel microchannels, denoted as Ag/TiO 2- x , has been fabricated by a simple microwave-assisted process employing vitamin C as the reducing agent for forming TiO 2- x framework followed by photochemical deposition of Ag particles. Charge transport and recombination processes were detected through transient photocurrent responses. The visible-light photocatalytic hydrogen production rate and the apparent reaction rate constant of RhB photodegradation with 3%-Ag/TiO 2- x catalyst are about 5.3 and 14.0 fold higher than those with the pristine macro-/meso-porous TiO 2 framework, respectively. A mechanism based on the synergistic effects of Ag plasmonics and Ti 3+ -doping at the Ag/TiO 2- x heterojunction is proposed, which consistently explains the high photocatalytic performance in hydrogen evolution and the improved photocatalytic decomposition of RhB under visible light. This study demonstrates the effective route to synthesize new heterojunction photocatalytic materials with multifunctional properties using low-cost and rapid microwave processes.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 21
·11437-11443
·
IF 7.443
Shusheng Pan,Xiaolin Liu,Min Guo,Siu fung Yu,Haitao Huang,Hongtao Fan,Guanghai Li
Ti3+-doped amorphous TiO2 nanoparticles (a-TiO2:Ti3+), which are an intermediate band semiconductor, were fabricated by high intensity ultraviolet pulsed laser ablation in water. The absorption band of a-TiO2:Ti3+ nanoparticles, which appears between the visible and infrared regions, is much wider than that of the rutile TiO2 nanoparticles. The intermediate band, which has a recombination lifetime of 0.71 μs, is found to be 1.61 eV above the valence band (VB) top of TiO2. It can be shown that the a-TiO2:Ti3+/TiO2 nanotube hybrid dye-sensitized solar cells (DSSCs) not only have a high fill factor and large open circuit voltage, but also have high photovoltaic conversion efficiency as compared to TiO2 nanotube DSSCs. Considering that most of the current solar cells use only a single photoelectric conversion material (PCM), our results will promote the research on multi-PCM hybrid solar cells.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）