Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Jinghao Hua,Sheng Feng,Changchang Ma,Haitao Huang,Kai Wei,Xiaojun Dai,Kaidi Wu,Haihong Wang,Zhaowei Bian
In this study, a novel 2D/2D Z-scheme Bi 5 O 7 Br/NiFe-LDH photocatalyst was prepared by combining NiFe-LDH with Bi 5 O 7 Br through self-assembly. Under simulated solar irradiation, compared with pure NiFe-LDH and Bi 5 O 7 Br, the 2D/2D Z-scheme Bi 5 O 7 Br/NiFe-LDH photocatalyst revealed a significant improvement in the efficiency of photocatalytic reduction of CO 2 . Z-scheme heterojunction promotes the separation of photo generated charge carriers and 2D/2D structure is conducive to exposing more active site and enhancing the migration rate of interface carriers. The photocatalytic activity experiment revealed that the CH 4 production efficiency of the Bi 5 O 7 Br/NiFe-LDH (37.77 μmol/g/h) after 8 h of light exposure was 2 times and 10 times that of Bi 5 O 7 Br (22.41 μmol/g/h) and NiFe-LDH (3.84 μmol/g/h), respectively. The successful formation of Z-scheme heterojunction was determined through band analysis and related characterization. The advantage of Z-scheme heterojunction is that it has high electron mobility and low resistivity. This work launches a feasible design strategy of special structure photocatalysts to enhance the photocatalytic activity for the CO 2 reduction.
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
Journal of the American Chemical Society
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2020
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IF 14.612
Peishen Li,Ziang Zhou,Qiang Wang,Ming Guo,Shaowei Chen,Jingxiang Low,Ran Long,Wen Liu,Peiren Ding,Yunyun Wu,Yujie Xiong
Photocatalytic nitrogen fixation represents a green alternative to the conventional Haber–Bosch process in the conversion of nitrogen to ammonia. In this study, a series of Bi5O7Br nanostructures were synthesized via a facile, low-temperature thermal treatment procedure, and their photocatalytic activity toward nitrogen fixation was evaluated and compared. Spectroscopic measurements showed that the tubular Bi5O7Br sample prepared at 40 °C (Bi5O7Br-40) exhibited the highest electron-transfer rate among the series, producing a large number of O2.– radicals and oxygen vacancies under visible-light photoirradiation and reaching a rate of photocatalytic nitrogen fixation of 12.72 mM·g–1·h–1 after 30 min of photoirradiation. The reaction dynamics was also monitored by in situ infrared measurements with a synchrotron radiation light source, where the transient difference between signals in the dark and under photoirradiation was analyzed and the reaction pathway of nitrogen fixation was identified. This was further supported by results from density functional theory calculations. The reaction energy of nitrogen fixation was quantitatively estimated and compared by building oxygen-enriched and anoxic models, where the change in the oxygen vacancy concentration was found to play a critical role in determining the nitrogen fixation performance. Results from this study suggest that Bi5O7Br with rich oxygen vacancies can be used as a high-performance photocatalyst for nitrogen fixation.
研究领域:
材料科学
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环境科学
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催化化学
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DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2021
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IF 8.271
Xue Chen,Ming-Yu Qi,Yue-Hua Li,Zi-Rong Tang,Yi-Jun Xu
The fabrication of efficient catalysts to reduce nitrogen (N 2 ) to ammonia (NH 3 ) is a significant challenge for artificial N 2 fixation under mild conditions. In this work, we demonstrated that the simultaneous introduction of oxygen vacancies (OVs) and Mo dopants into Bi 5 O 7 Br nanosheets can significantly increase the activity for photocatalytic N 2 fixation. The 1 mol% Mo-doped Bi 5 O 7 Br nanosheets exhibited an optimal NH 3 generation rate of 122.9 μmol g −1 h −1 and durable stability, which is attributed to their optimized conduction band position, suitable absorption edge, large number of light-switchable OVs, and improved charge carrier separation. This work provides a promising approach to design photocatalysts with light-switchable OVs for N 2 reduction to NH 3 under mild conditions, highlighting the wide application scope of nanostructured BiOBr-based photocatalysts as effective N 2 fixation systems.
研究领域:
材料科学
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催化
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光化学
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DOI
高影响因子
Materials Today Communications
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2023
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IF 3.8
Ran Feng,Jiazhi Meng,Hualei Yuan,Xu Zhang,Chunlang Gao,Chaogang Ban,Yizhong Guo,Kaiwen Wang
Cancers, Down’s syndrome, Alzheimer’s and other diseases of gene mutation always occur with anomalous changes of DNA nucleic acid base. Therefore, the development of highly sensitive and reproducible nucleic acid sensors that based upon surface enhanced Raman scattering (SERS) is of immense interest for clinical medical analysis and diagnosis. Herein, a rationally designed core-shell assembly of Au nanoparticle wrapped with Au doped Bi 5 O 7 Br nanotube with eliminated fluorescent background and notable chemical enhancement effect was exploited and served as a SERS sensor for detection of adenine. Especially, we found the fluorescent background was remarkably suppressed in Raman spectra by introducing Au element into Bi 5 O 7 Br. The sensor exhibited a maximum SERS enhancement factor of up to 5.45 × 10 7 and a detection limit as low as 10 −11 M after constructing Au nanoparticle/Au atom doped Bi 5 O 7 Br heterojunction . More importantly, good reproducibility and long term stability under work condition were achieved. To gain in-depth understanding into chemical mechanism (CM) of the Raman signal enhancement, density functional calculations (DFTs) were combined with atom-specific model derived via aberration corrected transmission electron microscope (AC-TEM) to demonstrate the enhanced charge transfer (CT) and substrate-adsorbate adsorption. The doping and coupling strategy holds the potential to fabricate high signal-to-noise ratio SERS sensors for other molecule detection.
研究领域:
生物医学工程
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分子生物学
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分析化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2019
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IF 5.107
Lulu Zhang,Xiuping Yue,Jianxin Liu,Junqiang Feng,Xiaochao Zhang,Changming Zhang,Rui Li,Caimei Fan
BiOBr-based composite photocatalysts had attracted extensive attention for efficient photocatalytic degradation aqueous organic pollutants in the past decade. However, the catalysis ability of photocatalyst is greatly limited by their intrinsic high recombination rate of photo-generated charge carriers. Herein, we solve this problem by constructing a novel 2D/3D Bi 5 O 7 Br/BiOBr heterojunction photocatalyst that was prepared via one-step facile hydrolysis process. The pure Bi 5 O 7 Br and pure BiOBr photocatalysts were also obtained by only adjusting the pH value of the mixed solution. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), optical and electric property analysis and etc. The results suggested that 2D Bi 5 O 7 Br nanosheets tightly attached to the surface of BiOBr 3D structure with nanoflakes self-assembled microsphere , which could increase the transfer and separation efficiency of photogenerated charges. Furthermore, the 2D/3D Bi 5 O 7 Br/BiOBr heterojunction exhibited superior visible light photocatalytic performance for carbamazepine (CBZ) degradation than pure BiOBr and pure Bi 5 O 7 Br, which owing to the enhanced separation of photoinduced electrons and holes. At last, the underlying photocatalytic mechanism is elucidated based on the band structure and radical scavenging experiments. This work provided a feasible design idea to one-step construct 2D/3D nanocomposite for pharmaceutical wastewater purification.
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
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
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IF 9.965
Fangxia Xie,Qing Xi,Houfen Li,Xuan Jian,Jianxin Liu,Xiaochao Zhang,Yawen Wang,Rui Li,Caimei Fan
Regulating electron density at the active site by electronic directional transport from special channels is an effective strategy to accelerate the reaction rate in photocatalytic water splitting. Here, a novel two dimensional/two dimensional (2D/2D) Bi 5 O 7 Br/Ti 3 C 2 heterojunction with special interfacial charge transfer channel was fabricated successfully via in-situ growth of Bi 5 O 7 Br on the surface of ultrathin Ti 3 C 2 by using a convenient hydrolysis method. The electrostatic attraction between Bi 3+ cations and electronegative Ti 3 C 2 ensures the construction of 2D/2D heterojunction and a strong intimate interface contact between Ti 3 C 2 and Bi 5 O 7 Br, which establishes an electronic transport channel, and shortens the charge transport distance, assuring excellent bulk-to-surface and interfacial charge transfer abilities. Meanwhile, X-ray photoemission spectroscopy (XPS) and density functional theory (DFT) calculation revealed that the local electron density at the Ti 3 C 2 active sites is remarkably increased because of the transfer of interfacial electrons from Bi 5 O 7 Br to Ti 3 C 2 , which is a key factor for enhancing the photocatalytic performance. Thus, the resultant Bi 5 O 7 Br/Ti 3 C 2 exhibits significant improvement on the performance of photocatalytic hydrogen evolution under visible light irradiation . The hydrogen evolution reaction rate obtained on the optimized Bi 5 O 7 Br/Ti 3 C 2 composite is 1.97 times higher than that of pristine Bi 5 O 7 Br. This work provides a new protocol for the construction of 2D/2D heterojunction photocatalytic systems and regulating electron density by electronic directional transporting.
研究领域:
材料科学
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光催化
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DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
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2023
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IF 4.5
Fang-xia XIE,Lu-lu ZHANG,Xiao ZHANG,Mei ZHANG,Xuan JIAN,Jian-xin LIU,Xiao-chao ZHANG,Ya-wen WANG,Rui LI,Cai-mei FAN
In order to simultaneously solve the problems of the poor light absorption capacity and high recombination rate of photogenerated carriers, Bi 5 O 7 Br photocatalyst with abundant ordered/disordered structures (O/D-Bi 5 O 7 Br) was prepared through a simple in situ disorder engineering. The prepared samples were characterized by XRD, TEM, HRTEM, SAED, XPS, UV-Vis diffuse reflectance spectra (DRS), and the activity was evaluated by photocatalytic degradation of tetracycline hydrochloride (TC) and hydrogen evolution under visible light irradiation. Results revealed that the ordered/disordered structure not only enhances the light absorption ability, uplifts conduction band position, facilitates the transfer and separation of photogenerated carriers, but also offers abundant unsaturated atoms as active sites for the photocatalytic process. Therefore, O/D-Bi 5 O 7 Br exhibits a high hydrogen evolution rate of 38.12 μmol/(g·h) and superior TC degradation rate of 86% within 135 min.
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
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