JOURNAL OF HAZARDOUS MATERIALS
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2020
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IF 9.038
Jie-hao Li,Jie Ren,Ying-juan Hao,Er-peng Zhou,Yue Wang,Xiao-jing Wang,Ran Su,Ying Liu,Xue-han Qi,Fa-tang Li
Constructing heterojunctions would result in the change of valence band position, which is an important factor determining the oxidative ability of photo-induced holes, has received scant attention. In this paper, β-Bi 2 O 3 /Bi 2 O 2 CO 3 composites with different ratios were obtained via ionic-liquid-assisted solvothermal and in-situ calcination processes. UV–vis DRS, Mott-Schottky test, and Kelvin probe measurement showed the change of band gaps of β-Bi 2 O 3 and Bi 2 O 2 CO 3 before and after heterojunction formation. SPV, ESR, photocurrent, and scavenger experiments identified the separation efficiency of photo-generated electrons and holes, as well as the active species generated in the photocatalytic process. The photocatalytic mechanism was investigated by the degradation of Rhodamine B (RhB) upon visible-light and simulated sunlight, respectively. The results demonstrated that β-Bi 2 O 3 /Bi 2 O 2 CO 3 heterojunctions possessed enhanced separation efficiency and higher degradation ability than the individuals under visible-light irradiation due to effective electron transfer. However, lower performance under simulated sunlight was observed, although their separation efficiency remained high. The decisive reason for this was that the up-shift of valence band of Bi 2 O 2 CO 3 induced by hybridization and the transition of holes from VB of Bi 2 O 2 CO 3 to that of β-Bi 2 O 3 with more negative potential decreased the oxidative ability of holes, which surpassed the positive influence of enhanced separation efficiency.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
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2017
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IF 9.446
Jian-guo Guo,Ying Liu,Ying-juan Hao,Yi-lei Li,Xiao-jing Wang,Rui-hong Liu,Fa-tang Li
Heterostructured Bi 3 O 4 Br/α-Bi 2 O 3 nanocomposites are prepared via in situ one-step self-combustion of ionic liquids. Tetrabutylammonium bromide (TBAB) is employed to be fuel, complexing agent for ionic liquids, as well as the reactant supplying Br for the objective material. The ratio of Bi 3 O 4 Br/α-Bi 2 O 3 can be easily adjusted by controlling the amount of TBAB. The heterojunctions show higher photocatalytic ability towards both azo dye methyl orange (MO) and colorless pollutant phenol . The electron spin resonance (ESR) test and p-nitro blue tetrazolium chloride (NBT) degradation result indicate that generation amounts of superoxide anion radicals ( O 2 − ) over heterojunctions are less than that over pure Bi 3 O 4 Br. Photoelectrochemical measurements show that separation efficiencies of photo-generated electrons and holes are decreased after the combination of Bi 3 O 4 Br and α-Bi 2 O 3 . Work function test and scavenger experiments display that holes play key role for pollutant degradation and the position of holes on α-Bi 2 O 3 is lowered via hybridization. Thus, the enhanced photocatalytic activity over composites can be attributed to the position decline of α-Bi 2 O 3 valence band, thus improving the reactivity of holes in direct oxidation of pollutants. In this case, valence band position is confirmed to be more important than separation efficiency of charge carriers in affecting photocatalytic performance.
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
CATALYSIS LETTERS
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2022
·Vol. 153
·期 4
·1109-1119
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IF 2.936
Ren Yanrong,Pu Hongzheng,Zeng Hanlu,Deng Chaofang,Yin Fengling,Wu Ya,Yang Dingfeng,Li Yuanyuan
Modulating the band edge position of a photocatalyst is important in photocatalysis. In this study, a more positive valence band position was realized by doping Sb in Li 2 SnO 3 . The downshifted valence band position was mainly attributed to the relatively low Sb energy level resulting from its higher electronegativity. Such band structure modification resulted in a stronger photo-oxidative capability for photogenerated holes (h + ), leading to an enhanced photodegradation rate toward tetracycline (TC) solution. For Li 2 Sn 0.9 Sb 0.1 O 3 , the efficiency reached 74% within 30 min, which was approximately 2.5 times that of Li 2 SnO 3 . Radical trapping experiments showed that h + played the dominant role in the photodegradation process. Finally, the photodegradation pathway was analyzed using liquid chromatography–mass spectrometry (LC–MS). These results might provide important insight for designing photocatalysts with high efficiency through band structure modification. Graphical Abstract
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
Inorganic Chemistry Frontiers
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2022
·Vol. 9
·期 14
·3578-3589
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IF 7.779
Jie-hao Lia,Rui-hong Liu,Meng Ning,Yi-lei Li,Ying Liu,Xinying Liu,Phathutshedzo Khangale,Diane Hildebrandt,Xiao-jing Wang,Fa-tang Li
Constructing heterostructured photocatalysts will generally improve the separation efficiency of photo-induced carriers; however, the change in the energy band position that affects their redox ability has received little attention. In this work, α-Bi2O3/Bi5NO3O7 heterojunctions are prepared via solution combustion synthesis and characterized by UV-vis DRS, Mott–Schottky and Kelvin probes, and the band structures of α-Bi2O3 and Bi5NO3O7 before and after the formation of the heterojunction are obtained. The results of the degradation of rhodamine B and tetracycline indicate that the main active species are holes and superoxide anion radicals, respectively. Although separation efficiency over heterojunctions is higher than that over individual Bi5NO3O7 and α-Bi2O3, lower degradation ability is observed. The reason is that the heterojunction formation causes an upward shift of the valence band of Bi5NO3O7 and a downward shift of the conduction band of α-Bi2O3, which reduces the oxidation ability of holes and the ability to activate molecular oxygen, respectively. The decrease in the redox ability outweighs the positive impact of enhanced separation efficiency.
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
Journal of Physical Chemistry C
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2022
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IF 4.177
Kang Hu,Ping Liu,Ziqing Zhang,Ji Bian,Guowei Wang,Hongjun Wu,Hui Xu,Liqiang Jing
g-C3N4 is a promising photocatalyst for CO2 conversion owing to its outstanding reduction potential. However, its shallow valence band position and sluggish water oxidation reaction restrict the overall CO2 photoreduction process. Herein, g-C3N4 nanosheets are first doped with B through thermal treatment of mixed NaBH4 and subsequently modified with highly dispersed Ru-oxo clusters by using tailored chitosan oligomers. The optimal Ru-oxo modified B-doped g-C3N4 exhibits an exceptional photocatalytic CO2 conversion rate with 22-fold improvement compared with pristine CN. Based on the results of electron paramagnetic resonance, atmosphere-controlled surface photovoltage spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy, etc., it is confirmed that the improved photoactivities are attributed to the downward shift of the valence band to obtain the strong driving force for water oxidation along with extension of the visible light response region by B doping and to the capture of photogenerated holes to enhance charge separation and then to accelerate the water oxidation process from the modified Ru-oxo clusters.
研究领域:
材料科学
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化学
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环境科学
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产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
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2024
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IF 4.3
Dingfeng Yang,Hongzheng Pu,Peng Dai,Wen Jiang,Yuanxue Yi,Tao Zhang,Shuming Zhang,Xichuan Guo,Yuanyuan Li
A systematic evaluation of enhancing photocatalysis via aliovalent cation doping is conducted. Cation In3+, being p-type-doped, was chosen to substitute the Sn site (Sn4+) in Li2SnO3, and the photodegradation of 2,4-dichlorophenol was applied as a model reaction. Specifically, Li2Sn0.90In0.10O3 exhibited superior catalytic performance; the photodegradation efficiency reached about 100% within only 12 min. This efficiency is far greater than that of pure Li2SnO3 under identical conditions. Density functional theory calculations reveal that introducing In3+ increased the electron mobility, yet decreased the hole mobility, leading to photogenerated carrier separation. However, photoluminescence and time-resolved photoluminescence suggest that In3+ induced nonradiative coupling in the matrix, reducing the photogenerated carrier separation ratio compared with that of Li2SnO3. The optical band gap of Li2Sn0.90In0.10O3 was almost unchanged compared with that of Li2SnO3 via ultraviolet–visible absorption. The increased photocatalytic efficiency was ascribed to the lower valence band position and enhanced hole concentrations by valence band X-ray photoelectron spectroscopy and electrochemical measurements. Finally, a 2,4-dichlorophenol degradation pathway, an intermediate toxicity assessment, and a photocatalytic mechanism were proposed. This work offers insights into designing and optimizing semiconductor photocatalysts with high performance.
研究领域:
材料科学
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环境化学
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光化学
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催化
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）