JOURNAL OF HAZARDOUS MATERIALS
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2020
·
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
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2014
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IF 6.007
Ruiping Hu,Xin Xiao,Shunheng Tu,Xiaoxi Zuo,Junmin Nan
Novel flower-like heterostructured β-Bi 2 O 3 /Bi 2 O 2 CO 3 microspheres are synthesized by calcining a Bi 2 O 2 CO 3 self-sacrifice precursor for the visible-light photocatalytic degradation of o -phenylphenol (OPP, is a widely used fungicide and preservative agent). The Bi 2 O 2 CO 3 microspheres are firstly prepared under hydrothermal conditions, and then converted to Bi 2 O 3 by thermal treatment. With increasing the calcining temperature from 250 to 500 °C, an in situ stepwise decomposition reaction take place during the course of calcination , described as: Bi 2 O 2 CO 3 → β-Bi 2 O 3 /Bi 2 O 2 CO 3 → β-Bi 2 O 3 → β-Bi 2 O 3 /α-Bi 2 O 3 → α-Bi 2 O 3 . The β-Bi 2 O 3 /Bi 2 O 2 CO 3 microspheres synthesized at 300 °C exhibit excellent photocatalytic activity under visible-light irradiation, which can degrade 99.8% OPP in 45 min. And the degradation rate of the heterostructured photocatalyst is approximately 2, 2.6, 6, 13, 80, and 827 times higher than that of single β-Bi 2 O 3 , mixed β-Bi 2 O 3 and Bi 2 O 2 CO 3 , commercial β-Bi 2 O 3 , α-Bi 2 O 3 , N-doped TiO 2 , and Bi 2 O 2 CO 3 , respectively. The superior photoreactivity of the β-Bi 2 O 3 /Bi 2 O 2 CO 3 is attributed to the enhanced charge separation and transfer due to the formation of p–n junction with large heterojunction interface, favorable band gap energy (2.27 eV), relatively high specific surface areas (12.5 m 2 g −1 ), and flower-like hierarchical micro/nano structures. In addition, the degradation intermediates including ethyl phenethyl ether, phenyl acetaldehyde, and phenylacetic acid are identified. And the results also reveal that the photogenerated holes and •O 2 − radicals are primarily reactive species in the photocatalytic system, which are the key factors responsible for the nearly complete mineralization of OPP.
研究领域:
材料科学
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环境科学
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光催化
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
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2019
·Vol. 45
·期 12
·15036-15047
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IF 3.45
Hui Zhou,Songtao Zhong,Ming Shen,Yufeng Yao
A three-dimensional (3D) flower-like β-Bi 2 O 3 /Bi 2 O 2 CO 3 heterojunction photocatalyst was synthesized via decomposition of the precursor fabricated using a composite soft template, which was constructed from dl -aspartic acid and nonionic amphiphilic triblock copolymer (Pluronic F127). The morphology, phase structure, composition , effect of reactant concentration, and possible formation mechanism were systematically studied. The results showed that dl -aspartic acid was chosen as the coordination- and structure-directing agent, while F127 was used as the capping agent during preparation of the precursor. The as-prepared flower-like β-Bi 2 O 3 /Bi 2 O 2 CO 3 heterojunction obtained after calcination of the self-sacrificing precursor at 290 °C showed excellent photocatalytic performance in the degradation of the refractory colorless antibiotic agent tetracycline (TC) under simulated sunlight irradiation, with 98.79% TC degradation being achieved within 60 min of irradiation. This excellent photocatalytic performance was attributed to the narrow band gap, heterojunction structure , and 3D hierarchical structure. The results further revealed that photogenerated holes (h + ) and hydroxyl radicals ( • OH) dominated the photocatalytic process. Furthermore, the β-Bi 2 O 3 /Bi 2 O 2 CO 3 heterojunction catalyst was not photocorroded after six consecutive cycles, suggesting an excellent photostability.
研究领域:
材料科学
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环境催化
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光催化
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纳米材料
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环境工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）