Frontiers of Environmental Science & Engineering
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2022
·Vol. 17
·期 2
·1-11
·
IF 6.048
Yang Fan,Li Junpeng,Wang Huan,Xiao Xiaofeng,Bai Rui,Zhao Feng
Manganese oxides are widely distributed in soils and sediments, affecting the migration and transformation of heavy metals and organic pollutants. The microbial conversion of soluble Mn(II) into insoluble Mn(III/IV) oxides is considered to be the initial source of manganese oxides in the environment; however, whether this process is related to a physiological role remains unclear. Here, we explored the microbial manganese oxidation process under visible light by using coastal surface seawater microorganisms. Visible light greatly promotes the oxidation rate of Mn(II), and the average rate reaches 64 µmol/(L·d). The generated manganese oxides were then conducive to Mn(II) oxidation, thus the rapid manganese oxidation was the result of the combined action of biotic and abiotic, and biological function accounts for 88 % ± 4 %. Extracellular superoxide produced by microorganisms induced by visible light is the decisive factor for the rapid manganese oxidation in our study. But the production of these superoxides does not require the presence of Mn(II) ions, the Mn(II) oxidation process was more like an unintentional side reaction, which did not affect the growth of microorganisms. More than 70 % of heterotrophic microorganisms in nature are capable of producing superoxide, based on the oxidizing properties of free radicals, all these bacteria can participate in the geochemical cycle of manganese. What’s more, the superoxide oxidation pathway might be a significant natural source of manganese oxide.
研究领域:
环境微生物学
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地球化学
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水文学与水资源
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
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IF 6.3
Jiahe Zhai,Hui Wang,Abdelkader Labidi,Long Zeng,Yu Huang,Chuanyi Wang
Removing low-concentration NO in the air by means of photocatalytic technology is a promising approach. Herein, our work pins down the mechanism of cobalt metal doping within the lattice of Bi 4 Ti 3 O 12 (BTO) for the photocatalytic NO conversion. As a result, the Co-BTO exhibits a NO conversion efficiency of 58.3 %, which is substantially higher than that of BTO (30 %). More interestingly, the Co-BTO also shows a lower production of intermediate NO 2 than that of the BTO. These findings demonstrate that within Co-BTO, both Co²⁺ and Co³ ⁺ coexist. The redox cycle between these two cobalt species engenders active sites possessing strong reducing capabilities for O₂ which can be adsorbed and activated at the Co sites, thereby generating superoxide radicals (•O₂⁻). Furthermore, the doping of a certain portion of cobalt broadened light absorption and enhanced the separation efficiency of photogenerated carriers, further facilitating the activation of O₂. Lastly, electron spin resonance (ESR) and in-situ diffuse reflective infrared Fourier transform spectroscopy (in-situ DRIFTS) were respectively utilized to further clarify the active species involved in the photocatalytic oxidation of NO and its adsorption and conversion pathways from a mechanistic standpoint. Overall, this work represents a novel endeavor for the advancement of visible-light-driven photocatalysts usage for environmental remediation against NO pollution.
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
RSC Advances
·
2016
·Vol. 6
·期 10
·7772-7779
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IF 3.289
Huiping Zhao,Yafang Zhang,Guangfang Li,Fan Tian,Han Tang,Rong Chen
Loose-packed flower-like BiOCl hierarchical nanostructures (HNs) assembled by thin nanosheets were successfully synthesized via a facile solvothermal method. Based on the matchability analysis of band structure of BiOCl and the molecular orbitals of the dyes, the RhB dye-sensitized heterogeneous BiOCl HNs system was established for MO degradation under visible light irradiation. The mechanism of MO degradation over RhB-sensitized BiOCl was also discussed according to the photocurrent and photoluminescence results. It was found that MO degradation efficiency over RhB-sensitized BiOCl HNs was obviously improved due to the generation of superoxide radicals (˙O2−) through the reduction of surface-adsorbed O2 molecules by the injected electrons on the conduction band of BiOCl HNs from the excited RhB molecules. This work may provide insight on better understanding the organic dye photodegradation process in RhB dye-sensitized BiOCl heterogeneous systems and explore a dye-sensitized semiconductor photocatalyst strategy for environmental remediation.
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
Cell Reports Physical Science
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2021
·
IF 0
Chenxi Dong,Xupeng Zong,Ziwen Liu,Lijuan Niu,Zhao Zhao,Li An,Dan Qu,Xiayan Wang,Zaicheng Sun
Molecular oxygen (O 2 ) activation is a critical step in the low-temperature catalytic oxidation of carbon monoxide (CO). Photocatalysis is a facile way to activate O 2 to superoxide radicals under mild conditions. Photothermal catalysis, which integrates the photocatalysis of semiconductors and the thermocatalysis of noble metals, has arisen as an appealing strategy to achieve low-temperature catalytic oxidation. Here, we report that Pd/PdO/CeO 2 shows that the temperature of 90% CO conversion dropped by 30°C–50°C under irradiation. The apparent activation energy reduces from 64.6 kJ ⋅ mol −1 to 44.6 kJ ⋅ mol −1 . Pd/PdO/TiO 2 and Pd/PdO/Al 2 O 3 are prepared and compared to understand the underlying mechanism. The results reveal that photocatalysis is vital in lowering the apparent activation energy besides the photothermal effect. The photo-generated electrons promote O 2 activation to generate the superoxide anion. The hole can activate the adsorbed CO on the PdO. These active species are beneficial for lowering the CO oxidation temperature.
研究领域:
化学
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环境科学
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材料科学
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DOI
PubMed
JOURNAL OF ALLOYS AND COMPOUNDS
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2016
·
IF 3.014
Jianxin Liu,Rui Li,Yunfang Wang,Yawen Wang,Xiaochao Zhang,Caimei Fan
For detecting the active roles of ZIF-8 in composite photocatalyst , a novel Ag/AgCl/ZIF-8(50%) composite photocatalyst was designately prepared by anchoring Ag/AgCl nanoparticles on the surface of ZIF-8 with 50% content. The adsorption and photocatalytic performance of Ag/AgCl/ZIF-8(50%) were conducted by removal of Rhodamine B (RhB) from aqueous solution under dark and visible light irradiation (λ > 420 nm). The experimental results showed that the as-synthesized Ag/AgCl/ZIF-8(50%) exhibited higher photocatalytic activity than Ag/AgCl. The XRD , TEM , FTIR, DRS, VB XPS, ESR, N 2 adsorption isotherms and active species trapping experiments were used to characterize the performance of the composite photocatalyst. We found that the ZIF-8 in composite photocatalyst not only has the adsorption ability for RhB by its large specific area, but also has the ability for the formation of O 2 · − by an appropriate position of conduction band (CB). A reasonable reaction mechanism with a new perspective on the composite photocatalyst of Ag/AgCl/ZIF-8(50%) was proposed. This insight on the active roles of ZIF-8 in Ag/AgCl/ZIF-8(50%) may open a window for the use of MOF material in photocatalytic field.
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 MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 16
·14954-14966
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IF 2.195
Fang Hongjun,Pan Yusong,Yin Minyuan,Pan Chengling
Active co-catalysts have been extensively used for improving photocatalytic activity in semiconductor-based photocatalytic systems. Herein, 2D alkalized Ti 3 C 2 (Ti 3 C 2 -OH) nano-sheets were coupled with CdS via a facile electrostatic self-assembly strategy and combined with hydrothermal method to prepare Ti 3 C 2 -OH/CdS photocatalyst. The morphologies, crystal phases, optical and photoelectrical properties of the prepared photocatalysts were characterized by XRD, SEM, TEM, FTIR, PL, and EIS analysis, respectively. The photocatalytic degradation results verified that the photo-degradation performance of Ti 3 C 2 -OH/CdS photocatalyst (degradation of 97% RhB in 100 min) was obviously superior to that of pure CdS (degradation of 70% RhB in 100 min) and Ti 3 C 2 /CdS (degradation of 82% RhB in 100 min). The active species trapping experiments for Ti 3 C 2 -OH/CdS photocatalyst revealed that the superoxide radical ( · O 2 − ) and holes (h + ) were the predominant species for degradation of RhB. Furthermore, the Ti 3 C 2 -OH co-catalyst in the Ti 3 C 2 -OH/CdS composite not only played the role of promoting the effective separation of photo-generated electron–hole pairs, but also constructing strong connections with CdS semiconductor to establish heterostructure, ultimately enhancing the photocatalytic performance of the Ti 3 C 2 -OH/CdS photocatalyst.
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 Energy Chemistry
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2022
·
IF 13.599
Xianwen Zhang,Zheng Li,Bin Zeng,Can Li,Hongxian Han
Understanding the processes of charge generation, transfer and capture is important for the design and synthesis of efficient photocatalysts. In this work, light-induced charge separation and effect of O 2 on electron transfer processes in SrTiO 3 were investigated by electron paramagnetic resonance (EPR). It was found that photoinduced electron transfer from O 2− to Ti 4+ produced Ti 3+ and O − redox radical pairs under vacuum condition. Under oxygen atmosphere, however, surface bound superoxide radicals O 2 − were formed by electron reduction of adsorbed oxygen at initial photoirradiation stage, and quenched by the reverse electron transfer to Ti 4+ upon further photoirradiation. Formation of long-lived charge separation associated [Ti 3+ ---O − ] species and the reversibility of surface bound superoxide radicals mediating the processes of photogenerated electrons may be accountable for the high activity of SrTiO 3 in photocatalytic water splitting reaction.
研究领域:
材料科学
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物理化学
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高影响因子
ChemSusChem
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2022
·Vol. 15
·期 19
·e202201068
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IF 9.14
Meijiang Liu,Huifang Liu,Ning Li,Chaofeng Zhang,Jian Zhang,Feng Wang
Graphical Selectivity under control : The synergistic action of photogenerated holes and superoxide radicals could selectively oxidize the C−C bond breakage to generate formic acid. And the generation of hydroxyl radicals was inhibited in favor of solving the over-oxidation of formic acid. Photocatalysis is a promising technology for conversion of the glycerol into formic acid, but photocatalytic oxidation of C−C bonds in glycerol exhibits poor selectivity towards formic acid because the photogenerated radicals (e.g., hydroxyl radicals) further oxidize formic acid to CO 2 . In this work, a synergy of photogenerated holes and superoxide radicals that achieved the selective oxidation of glycerol into formic acid over the TiO 2 catalyst was revealed. The charge separation of pristine TiO 2 was improved with the aid of oxygen, which resulted in efficient hole oxidation of the C−C bonds in glycerol to formic acid. Surface active species were controlled to prevent being converted to hydroxyl radicals on TiO 2 by controlling the oxygen and water contents, which solved the problem of formic acid peroxidation without sophisticated catalyst modifications. Mechanism studies suggested that glyceraldehyde and glycolaldehyde were the intermediates to generate formic acid. This work provides a green and efficient approach to produce formic acid as a liquid hydrogen carrier from bio-based alcohols.
研究领域:
化学工程
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环境科学
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材料科学
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DOI
PubMed
高影响因子
CHEMOSPHERE
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2021
·
IF 7.086
Ran Ma,Sai Zhang,Xuewei Liu,Mingtai Sun,Jianzhong Cao,Jian Wang,Suhua Wang,Tao Wen,Xiangke Wang
Two-dimensional (2D) bismuth-based semiconductors have aroused intensive concern owing to their prominent photocatalytic activity for organic pollutants removal . In this work, a facile strategy for introducing oxygen vacancy in Bi-based oxyiodides (Bi x O y I z ) sheet-like architectures to activate molecular oxygen was proposed. The structure, photoelectric properties and visible light (λ > 420 nm) induced photocatalytic activities of these samples for decomposition of bisphenol A (BPA) were systematically characterized and evaluated. The as-prepared Bi 7 O 9 I 3 with a feeding Bi/I molar ratio of 1:1 exhibited the best photocatalytic activity comparable to those of similarly synthesized Bi 7 O 9 I 3 with other molar ratios and BiOIO 3 catalysts. The optimal Bi 7 O 9 I 3 achieved excellent photocatalytic activity with 99.6 % degradation efficiency of BPA within 20 min and superior structural stability with 95.1 % degradation retention over 5 cycling tests. In addition, the resulting Bi 7 O 9 I 3 sample displayed a high mineralization efficiency of BPA. Importantly, the plenty of oxygen vacancies (V o s) exsiting in Bi 7 O 9 I 3 played the dominant role in both accelerating electron transfer and activating molecular oxygen to facilitate the generation of superoxide radical (O 2 ·- ) and singlet oxygen ( 1 O 2 ), thereby proceeding oxidative degradation of BPA molecules during photoreactions. The efforts and attempts are also extendable to synthesis other 2D photocatalysts, providing potential for effective charge-carrier separation and molecular oxygen activation.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ruizheng Xu,Guiyu Wei,Zhemin Xie,Sijie Diao,Jianfeng Wen,Tao Tang,Li Jiang,Ming Li,Guanghui Hu
Increasing the efficiency of charge transfer and separation efficiency of photogenerated carriers are still the main challenges in the field of semiconductor-based photocatalysts. Herein, we synthesized g-C 3 N 4 @V 2 C MXene photocatalyst by modifying g-C 3 N 4 using V 2 C MXene. The prepared photocatalyst exhibited outstanding photocatalytic performance under visible light. The degradation efficiency of methyl orange by g-C 3 N 4 @V 2 C MXene photocatalyst was as high as 94.5%, which is 1.56 times higher than that by g-C 3 N 4 . This was attributed to the V 2 C MXene inhibiting the rapid recombination of photogenerated carriers and facilitating rapid transfer of photogenerated electrons (e − ) from g-C 3 N 4 to MXene. Moreover, g-C 3 N 4 @V 2 C MXene photocatalyst showed good cycling stability. The photocatalytic performance was higher than 85% after three cycles. Experiments to capture free radicals revealed that superoxide radicals (·O 2 − ) are the main contributors to the photocatalytic activity. Thus, the proposed g-C 3 N 4 @V 2 C MXene photocatalyst is a promising visible-light catalyst.
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
WATER SCIENCE AND TECHNOLOGY
·
2024
·Vol. 89
·期 3
·823-837
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IF 2.5
Zhang Jie,Wu Zhaochang,Dong Ben,Ge Sijie,He Shilong
View large Download slide View large Download slide Close modal Quinoline inevitably remains in the effluent of coking wastewater treatment plants due to its bio-refractory nature, which might cause unfavorable effects on human and ecological environments. In this study, MnCe x O y was consciously synthesized by α -MnO 2 doped with Ce 3+ (Ce:Mn = 1:10) and employed as the ozonation catalyst for quinoline degradation. After that, the removal efficiency and mechanism of quinoline were systematically analyzed by characterizing the physicochemical properties of MnCe x O y , investigating free radicals and monitoring the solution pH. Results indicated that the removal rate of quinoline was greatly improved by the prepared MnCe x O y catalyst. Specifically, the removal efficiencies of quinoline could be 93.73, 62.57 and 43.76%, corresponding to MnCe x O y , α -MnO 2 and single ozonation systems, respectively. The radical scavenging tests demonstrated that • OH and • O 2 - were the dominant reactive oxygen species in the MnCe x O y ozonation system. Meanwhile, the contribution levels of • OH and • O 2 - to quinoline degradation were about 42 and 35%, respectively. The abundant surface hydroxyl groups and oxygen vacancies of the MnCe x O y catalyst were two important factors for decomposing molecular O 3 into more • OH and • O 2 - . This study could provide scientific support for the application of the MnCe x O y /O 3 system in degrading quinoline in bio-treated coking wastewater. MnCe x O y Ce 3+ , MnCe x O y • OH and • O 2 - MnCe x O y were successfully synthesized by α-MnO 2 doped with Ce 3+ . The by abundant oxygen vacancies and surface hydroxyl groups of the MnCe x O y catalyst enhanced its catalytic activity. • OH and • O 2 - formation contributed to quinoline degradation in the MnCe x O y ozonation system.
研究领域:
环境科学
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化学工程
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DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Jialei Hui,Rong Wu,Yali Zhu,Zhilong Zhang,Shunhang Wei,Fangping Ouyang
Ternary metal chalcogenides as promising photocatalysts and introducing carbon quantum dots (CQDs) as a dopant to enhance their photocatalytic activity. In this study, MoIn 2 S 4 and MoIn 2 S 4 /CQDs composite photocatalysts were successfully synthesized utilizing an in-situ hydrothermal method, in which citric acid served as both the carbon source and surfactant. Among the prepared catalysts, the MoIn 2 S 4 /CQDs composite photocatalyst with the optimal ratio (MoIS/CQDs-1.0 g) exhibited the highest photocatalytic performance, achieving a removal rate of 94.4 % for methylene blue (MB) after 60 min of simulated solar illumination. The superior performance was primarily attributed to the upconversion photoluminescence effect of CQDs , which enhanced the light absorption of MoIn 2 S 4 . Also, the few-layer configuration of MoIn 2 S 4 as a matrix possessed numerous active sites to significantly minimize the aggregation of CQDs . Furthermore, the CQDs acted as electron acceptors and transport centers, inhibiting the rapid recombination of photogenerated carriers and accelerating electron transfer. Additionally, through trapping experiments and electron paramagnetic resonance (EPR) tests, the primary active species responsible for photocatalytic degradation was identified as superoxide radicals (·O 2 – ). Based on these findings, a possible photocatalytic mechanism for MoIS/CQDs-1.0 g was proposed. This study provided a novel, stable and efficient MoIn 2 S 4 modified with CQDs photocatalyst for water treatment.
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
危险品化学品经营许可证（带存储）