INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2022
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IF 4.326
Yunxia Bai,Mei Li,Xuemei Liu,Jinyu Han,Xinli Zhu,Qingfeng Ge,Hua Wang
Photocatalytic CO2 reduction is a promising route to simultaneously address two critical issues related to the energy and environment. Herein, a direct Z-scheme photocatalytic system, Ti3+ defective TiO2/CdS nanoflowers, was fabricated to enhance the production of C1–C3 products from CO2 reduction. First, nanoflower-like TiO2 (NF-TiO2) is prepared using a TiB2 precursor to build in Ti3+ defects. Then, the NF-TiO2/CdS heterojunctions are constructed via the sulfurization of TiO2/Cd-MOF. Importantly, the optimal heterojunction photocatalyst NF-TiO2/CdS0.6 exhibits a highly promoted CO2 reduction activity not only for CO and CH4 but also for C2–C3 hydrocarbons. The cumulative yields of CO and CH4 are 1007.0 μmol/g and 83.5 μmol/g (2.5 h), respectively, and a yield of 55.3 μmol/g (2.5 h) of C2–C3 hydrocarbons is obtained. This enhanced yield of C1–C3 products is attributed to the synergistic effects of abundant Ti3+ defects that increase adsorption and activation of CO2, the large surface area that provides sufficient active sites, and a direct Z-scheme heterojunction with a good intimate contact interface that effectively separates charge carriers and accumulates electrons with strong reducibility. Moreover, the photoluminescence analysis of hydroxyl radicals was conducted to provide evidence for the direct Z-scheme mechanism. This work provides a facile method for the construction of a TiO2-based direct Z-scheme photocatalytic system for improving photocatalytic performance toward CO2 reduction.
研究领域:
材料科学
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环境科学
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能源科学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2018
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IF 4.439
Lina Kong,Xintong Zhang,Changhua Wang,Jianping Xu,Xiwen Du,Lan Li
Artificial direct Z-scheme system is promising in solar-fuel production owing to their efficient charge separation and high redox capability. However, direct Z-scheme system suffers from how to construct reasonable interfacial charge transfer channel for selective charge recombination. Here we fabricate a direct Z-scheme system consisting of g-C 3 N 4 crumpled sheet with Ti 3+ -doped TiO 2 nanoparticles via polycondensation of urea with TiO 2 followed by hydrogenated treatment. UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) manifest that the hydrogenated treatment conferred Ti 3+ defect states below the conduction band minimum (CBM) of TiO 2 and improved visible light absorption of the g-C 3 N 4 /Ti 3+ -doped TiO 2 composite. The g-C 3 N 4 /Ti 3+ -doped TiO 2 exhibits remarkable photocatalytic performance for water splitting and degradation of pollutants than that of g-C 3 N 4 /TiO 2 , C 3 N 4 , and TiO 2 . The H 2 evolution rates of g-C 3 N 4 /Ti 3+ -doped TiO 2 reach up to 1938 and 287 μmol·h −1 ·g −1 under solar-light and visible-light irradiation, which is 3.4 and 2.8 times higher than that of g-C 3 N 4 /TiO 2 . The enhanced photocatalytic activity is ascribed to the Ti 3+ defects assistant formation of g-C 3 N 4 /Ti 3+ -doped TiO 2 Z-scheme photocatalyst, which results in efficient interfacial charge emigration and separation. Our work points out the critical role of defects in construction of Z-scheme pathways for charge transfer and provides possibilities for developing the other efficient photocatalysts.
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
Catalysts
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2019
·Vol. 9
·期 11
·927
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IF 3.444
Aiguo Han,Mei Li,Shengbo Zhang,Xinli Zhu,Jinyu Han,Qingfeng Ge,Hua Wang
In recent years, defective TiO2-based composite nanomaterials have received much attention in the field of photocatalysis. In this work, TiB2was used as a precursor to successfully prepare Ti3+defective TiO2(TiO2-B) with a truncated bipyramidal structure by a one-step method. Then, the SnS2nanosheets were assembled onto the as-prepared TiO2-B through simple hydrothermal reaction. TiO2-B exhibits strong visible light absorption properties, but the recombination rate of the photo-generated electron-hole pair was high and does not exhibit ideal photocatalytic performance. Upon introducing SnS2, the heterojunction catalyst SnS2-Ti3+defective TiO2(SnS2/TiO2-B) not only possesses the strong light absorption from UV to visible light region, the lowest photo-generated charge recombination rate but also achieves a more negative conduction band potential than the reduction potential of CO2to CO, and thereby, exhibits the significantly enhanced selectivity and yield of CO in photocatalytic CO2reduction. Notably, SnS2/TiO2-B produces CO at a rate of 58 µmol·h−1·g−1with CO selectivity of 96.3% under visible light irradiation, which is 2 and 19 times greater than those of alone TiO2-B and SnS2, respectively. Finally, a plausible photocatalytic mechanism on SnS2/TiO2-B was proposed that the electron transfer between TiO2and SnS2follows the Z-scheme mode. Our results present an effective way to gain highly efficient TiO2based photocatalysts for CO2reduction by combining different modification methods of TiO2and make full use of the synergistic effects.Keywords:photocatalytic CO2reduction;TiO2nanoplates;SnS2nanosheets;Ti3+defective TiO2
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
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2024
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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
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2020
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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
APPLIED SURFACE SCIENCE
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2024
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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
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环境科学
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产品关联
DOI
高影响因子
Catalysts
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2020
·Vol. 10
·期 5
·539
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IF 3.52
Lan Luo,Tingting Zhang,Xin Zhang,Rongping Yun,Yanjun Lin,Bing Zhang,Xu Xiang
Hydrogen production by photoreforming of biomass-derived ethanol is a renewable way of obtaining clean fuel. We developed a site-specific deposition strategy to construct supported Au catalysts by rationally constructing Ti3+defects inTiO2nanorods and Cu2O-TiO2p-n junction across the interface of two components. The Au nanoparticles (~2.5 nm) were selectively anchored onto either TiO2nanorods (Au@TiO2/Cu2O) or Cu2O nanocubes (Au@Cu2O/TiO2) or both TiO2and Cu2O (Au@TiO2/Cu2O@Au) with the same Au loading. The electronic structure of supported Au species was changed by forming Au@TiO2interface due to the adjacent Ti3+defects and the associated oxygen vacancies while unchanged in Au@Cu2O/TiO2catalyst. The p-n junction of TiO2/Cu2O promoted charge separation and transfer across the junction. During ethanol photoreforming, Au@TiO2/Cu2O catalyst possessing both the Au@TiO2interface and the p-n junction showed the highest H2production rate of 8548 μmol gcat−1h−1under simulated solar light, apparently superior to both Au@TiO2and Au@Cu2O/TiO2catalyst. The acetaldehyde was produced in liquid phase at an almost stoichiometric rate, and C−C cleavage of ethanol molecules to form CH4or CO2was greatly inhibited. Extensive spectroscopic results support the claim that Au adjacent to surface Ti3+defects could be active sites for H2production and p-n junction of TiO2/Cu2O facilitates photo-generated charge transfer and further dehydrogenation of ethanol to acetaldehyde during the photoreforming.Keywords:ethanol reforming;hydrogen production;Au catalyst;Ti3+defect;site-specific deposition
研究领域:
材料科学
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催化化学
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可再生能源
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产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2024
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IF 5.5
Ming Du,Xianzhi Yang,Chuye Quan,Huajie Huang,Wei Chen,Jianping Yang,Jian Zhang,Xinbao Zhu,Xing'ao Li
Background Rational design and construction of efficient electrocatalysts are crucial for enhancing the activity and stability of the hydrogen evolution reaction (HER) in alkaline electrolytes. Methods Herein, heteroatom (phosphorus and sulfur)-functionalized and self-adapting Ti 3+ species defect decorated Ti 3-x C 2 T y MXene (PS-TCT) with 3D porous architecture for anchoring platinum-nickel (PtNi) bimetallic nanocrystals for alkaline electrocatalytic HER. Experimental and theoretical studies have shown that the heteroatoms delicately modulated the electronic configuration of MXene to optimize the adsorption capacity of the reaction intermediates. The 3D porous spatial configuration of PS-TCT with abundant Ti 3+ species defect endowed an efficient channel for charge transfer and sufficient catalytically active sites, thus facilitating fast dynamics and long-term stability. Additionally, the strong bimetal-substrate interfacial interaction (Pt-S bonding) between PtNi and PS-TCT established an electron directional transport channel, thus achieving valid and stable interfacial electron transport. Significant findings Consequently, the optimized PtNi@PS-TCT nanohybrids showed remarkable catalytic activity with low overpotentials of 56.1 mV at 10 mA cm −2 and impressive Tafel slope of 81 mV dec −1 for HER in alkaline electrolytes (1.0 M KOH), while exhibiting outstanding electrochemical stability. This work offers a constructive route for precisely constructing high-performance multifunctional composite electrocatalysts.
研究领域:
材料科学
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电化学
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催化科学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2020
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IF 6.182
Qi Wang,Baker Rhimi,Hui Wang,Chuanyi Wang
To solve the aggregation problem of TiO 2 nanomaterials and improve the catalytic efficiency, F-doped TiO 2 /exfoliated bentonite (TF/EB) composite was prepared by dispersing F-doped TiO 2 (TF) nanoparticles on an exfoliated bentonite (EB) using a facile sol–gel method. The exfoliated bentonite was prepared by liquid-exfoliation method from the natural bentonite (B). The prepared samples were applied for toluene degradation in gas phase under UV and visible light irradiation. The as-prepared TF/EB composite exhibited higher toluene degradation efficiency than that of pure TiO 2 , F-doped TiO 2 and TF/B composite. Results indicated that the calcination temperature and the initial F/Ti atom ratio of reaction precursors greatly affected the photocatalytic activity towards toluene degradation. The best photocatalytic performance was obtained by the sample calcinated at 400 °C with an initial F/Ti atom ratio of 5%. The improved photocatalytic performance is ascribed to a series of benefits introduced by F-doping and exfoliation process. The presence of F - ions increases the percentage of exposed reactive {0 0 1} facets on TiO 2 . Moreover, F - ions incorporated into the TiO 2 lattice generate oxygen vacancies and Ti 3+ defects, which influence the transfer and migration of the photoinduced charge carriers and induce a visible-light photocatalytic activity . Furthermore, the electrostatic interaction of negatively charged exfoliated bentonite surface leads to a more efficient separation of charge carriers.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）