物理化学学报 >> 2022, Vol. 38 >> Issue (7): 2111008.doi: 10.3866/PKU.WHXB202111008

所属专题: 异质结光催化材料

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二维/一维BiOBr0.5Cl0.5/WO3 S型异质结助力光催化CO2还原

朱弼辰1, 洪小洋1, 唐丽永1,*(), 刘芹芹1, 唐华2,*()   

  1. 1 江苏大学,材料科学与工程学院,江苏 镇江 212013
    2 青岛大学,环境科学与工程学院,山东 青岛 266071
  • 收稿日期:2021-11-04 录用日期:2021-12-01 发布日期:2021-12-06
  • 通讯作者: 唐丽永,唐华 E-mail:1000003184@mail.ujs.edu.cn;huatang79@163.com
  • 作者简介:第一联系人:

    Contributed to this work equally.

  • 基金资助:
    国家自然科学基金(21975110);国家自然科学基金(21972058);山东省泰山青年学者项目资助

Enhanced Photocatalytic CO2 Reduction over 2D/1D BiOBr0.5Cl0.5/WO3 S-Scheme Heterostructure

Bichen Zhu1, Xiaoyang Hong1, Liyong Tang1,*(), Qinqin Liu1, Hua Tang2,*()   

  1. 1 School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu Province, China
    2 School of Environmental Science and Engineering, Qingdao University, Qingdao 266071, Shandong Province, China
  • Received:2021-11-04 Accepted:2021-12-01 Published:2021-12-06
  • Contact: Liyong Tang,Hua Tang E-mail:1000003184@mail.ujs.edu.cn;huatang79@163.com
  • About author:Email: huatang79@163.com (H.T.)
    Email: 1000003184@mail.ujs.edu.cn (L.T.)
  • Supported by:
    the National Natural Science Foundation of China(21975110);the National Natural Science Foundation of China(21972058);Prof. H. Tang gratefully acknowledges financial support from Taishan Youth Scholar Program of Shandong Province

摘要:

S型异质结不但可以提高载流子的分离效率,还可以维持较强的氧化还原能力。因此,构建S型异质是提高光催化二氧化碳还原反应的有效途径。本研究通过静电自组装法构建了具有近红外光响应(> 780 nm)的二维BiOBr0.5Cl0.5纳米片和一维WO3纳米棒S型异质结光催化剂,并用于高效还原二氧化碳。能带位置和界面电子相互作用的综合分析表明:在光催化二氧化碳还原反应过程中,BiOBr0.5Cl0.5/WO3遵循S型电子转移路径;不仅提高了载流子的高效分离,还维持了两相(BiOBr0.5Cl0.5和WO3)较高的氧化还原能力。此外,二维纳米片/一维纳米棒的结构使得半导体之间具备良好的界面接触,有利于载流子的分离,且暴露更多的活性位点,最终提高催化效率。结果显示,BiOBr0.5Cl0.5/WO3异质结催化剂表现出较高的CO2还原能力和CO选择性,CO的产率高达16.68 μmol∙g-1∙h-1,分别是BiOBr0.5Cl0.5的1.7倍和WO3的9.8倍。本工作为构建S型二维/一维异质结光催化剂高效还原二氧化碳提供了新的思路。

关键词: 二维/一维异质结构, BiOBr0.5Cl0.5纳米片, WO3纳米棒, 二氧化碳还原, S型异质结

Abstract:

Catalytic reduction of CO2 to CO has been considered promising for converting the greenhouse gas into chemical intermediates. Compared to other catalytic methods, photocatalytic CO2 reduction, which uses solar energy as the energy input, has attracted significant attention because it is a clean and inexhaustible resource. Therefore, using high-performance photocatalysts for effective CO2 reduction under mild reaction conditions is an active research hotspot. However, several current photocatalysts suffer from low solar energy conversion efficiency due to the extensive charge recombination and few active sites, leading to low CO2 reduction efficiency. Generally, constructing an S-scheme heterojunction can not only promote charge separation but also help maintain strong redox ability. Therefore, the S-scheme heterojunction is expected to help in achieving high conversion activity and CO2 reduction efficiency. Here, 2D tetragonal BiOBr0.5Cl0.5 nanosheets and hexagonal WO3 nanorods were prepared using a simple hydrothermal synthesis method, and the 2D/1D BiOBr0.5Cl0.5 nanosheets/WO3 nanorods (BiOBr0.5Cl0.5/WO3) S-scheme heterojunction with near infrared (NIR) light (> 780 nm) response were prepared via the electrostatic self-assembly method for the photocatalytic CO2 reduction. Following characterization and analysis, including diffuse reflectance spectra (DRS), Mott-Schottky plots, transient photocurrent response, time-resolution photoluminescence spectrum (TRPL), electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and electron spin resonance (ESR) measurements, it can be demonstrated that an S-scheme carrier transfer route was formed between the 2D BiOBr0.5Cl0.5 nanosheets and 1D WO3 nanorods. Driven by the internal electric field, which was formed between the two semiconductors, electron migration was boosted, thus inhibiting the recombination of photogenerated carriers, while the stronger redox ability was maintained, thus providing good reduction efficiency over BiOBr0.5Cl0.5/WO3 composite in CO2 reduction. In addition, the 2D/1D nanosheet/nanorod structure allowed for enhanced interface contact with abundant active sites, which favored charge separation and increased photocatalytic activity. Furthermore, the amount of WO3 nanorods added during the preparation of the composites was altered, which led to the optimal amount of 5% (w, mass fraction) for the photocatalytic CO2 reduction. As a result, the BiOBr0.5Cl0.5/WO3 composite exhibited superior photocatalytic reduction performance with a CO yield of 16.68 μmol·g-1·h-1 in the presence of any precious metal cocatalyst or sacrificial agent, which was 1.7 and 9.8 times that of pure BiOBr0.5Cl0.5 and WO3, respectively. In addition, the BiOBr0.5Cl0.5/WO3 composite provided continuously increased CO yields with excellent selectivity under full-spectrum light irradiation, suggesting good photocatalytic stability. This work describes a novel idea for the construction of 2D/1D S-scheme heterojunction photocatalysts for efficient CO2 reduction.

Key words: 2D/1D heterostructure, BiOBr0.5Cl0.5 nanosheets, WO3 nanorods, CO2 reduction, S-scheme

MSC2000: 

  • O643