Acta Phys. -Chim. Sin. ›› 2022, Vol. 38 ›› Issue (7): 2111008.doi: 10.3866/PKU.WHXB202111008

Special Issue: Heterojunction Photocatalytic Materials

• ARTICLE • Previous Articles     Next Articles

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

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