Sn and dual-oxygen-vacancy in the Z-scheme Bi2Sn2O7/Sn/NiAl-layered double hydroxide heterojunction synergistically enhanced photocatalytic activity toward carbon dioxide reduction

Shiming Zhang; Songyu Fan; Ting Liang; Jingwen Wei; Tingting Zhu; Yuxiang Shen; Zebin Yu; Hongxiang Zhu; Shuangfei Wang; Yanping Hou

doi:10.1016/j.jcis.2023.08.145

Sn and dual-oxygen-vacancy in the Z-scheme Bi₂Sn₂O₇/Sn/NiAl-layered double hydroxide heterojunction synergistically enhanced photocatalytic activity toward carbon dioxide reduction

J Colloid Interface Sci. 2023 Dec 15;652(Pt B):1126-1137. doi: 10.1016/j.jcis.2023.08.145. Epub 2023 Aug 24.

Authors

Affiliations

¹ School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China.
² School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning 530004, China.
³ College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China.
⁴ College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China; Guangxi Bossco Environmental Protection Technology Co., Ltd, 12 Kexin Road, Nanning 530007, China.
⁵ School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; Key Laboratory of Environmental Protection (Guangxi University), Education Department of Guangxi Zhuang Autonomous Region, Nanning 530004, China. Electronic address: houyp@gxu.edu.cn.

PMID: 37657213
DOI: 10.1016/j.jcis.2023.08.145

Abstract

Photocatalytic conversion of carbon dioxide (CO₂) into high value-added chemicals is an attractive yet challenging process, primarily due to the readily recombination of hole-electron pairs in photocatalysts. Herein, dual-oxygen-vacancy mediated Z-scheme Bi₂Sn₂O₇/Sn/NiAl-layered double hydroxide (V_O,O-20BSL) heterojunctions were hydrothermally synthesized and subsequently modified with Sn monomers to enhance photocatalytic activity toward CO₂ reduction. The abundance of oxygen vacancies endowed the V_O,O-20BSL with extended optical adsorption, enhanced charges separation, and superior CO₂ adsorption and activation. The interfacial charges transfer of the V_O,O-20BSL was demonstrated to follow a Z-scheme mechanism via photochemical deposition of metal/metal oxide. Under visible light irradiation, the V_O,O-20BSL exhibited the highest yields of carbon monoxide (CO) and methane (CH₄), with values of 72.03 and 0.85 umol·g^-1·h^-1, respectively, which were 2.66 and 1.57 times higher than that of the V_O-NiAl-layered double hydroxide (V_O-1LDH). In situ diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) revealed that carboxylic acid groups (COOH*) and aldehyde groups (CHO*) were the predominant intermediates during CO₂ reduction, and accordingly, possible CO₂ reduction pathways and mechanism were proposed. This study presents a feasible approach to incorporate dual vacancies into Z-scheme heterojunctions for CO₂ reduction.

Keywords: CO(2) photoreduction; CO(2) reduction intermediates; Dual oxygen vacancies; Interfacial charge transfer; Z-scheme Bi(2)Sn(2)O(7)/Sn/NiAl-LDH heterojunction.