Photocatalytic CO2 reduction of Ag/Ag2S/Ti3C2T X heterojunctions with enhanced interfacial charge transfer

Bo Zhang; Yijun Chen; Fei Li; Yang Zhang; Xiang Li; Wuwan Xiong; Weili Dai

doi:10.1039/d4na00969j

Photocatalytic CO₂ reduction of Ag/Ag₂S/Ti₃C₂T _X heterojunctions with enhanced interfacial charge transfer

Nanoscale Adv. 2024 Dec 30. doi: 10.1039/d4na00969j. Online ahead of print.

Authors

Bo Zhang^{1

2}, Yijun Chen³, Fei Li^{2

4}, Yang Zhang¹, Xiang Li¹, Wuwan Xiong¹, Weili Dai⁵

Affiliations

¹ College of Environmental and Chemical Engineering, Zhaoqing University Zhaoqing 526061 P. R. China [email protected].
² The Key Lab of Pollution Control and Ecosystem Restoration in Industry Cluster Ministry of Education, South China University of Technology P. R. China.
³ School of Environment and Energy, South China University of Technology Guangzhou 510006 P. R. China.
⁴ School of Environmental Science and Engineering, Sun Yat-Sen University Guangzhou 510275 P. R. China [email protected].
⁵ Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University Nanchang 330063 P. R. China.

Abstract

Photocatalytic reduction of CO₂ to produce organic fuels is a promising strategy for addressing carbon reduction and energy scarcity. Transition metal carbides (Ti₃C₂T _X ) are of particular interest due to their unique layered structures and excellent electrical conductivity. However, the practical application of Ti₃C₂T _X is limited by the poor separation efficiency of photogenerated charge carriers and the low migration ability of photogenerated electrons. Herein, Ag/Ag₂S/Ti₃C₂T _X heterojunctions were synthesized by depositing Ag/Ag₂S nanoparticles onto layered Ti₃C₂T _X substrates using a combination of co-precipitation and photoreduction methods. Fluorescence spectra, UV diffuse reflection, and photoelectric chemical characterizations demonstrated that Ag/Ag₂S/Ti₃C₂T _X heterojunctions provided effective channels for the reverse and synergistic migration of electrons and holes, leading to improved spatial separation. Notably, the Ag component in the composite acts as an electron acceptor and reactive center, significantly enhancing the migration ability of photogenerated electrons. The total alcohol yield over Ag/Ag₂S/Ti₃C₂T _X (125.3 μmol g_catal. ^-1) was 5.1 times higher than that on Ag₂S (24.7 μmol g_catal. ^-1) and 2.1 times higher than on Ti₃C₂T _X (60.7 μmol g_catal. ^-1). This study offers valuable insights into designing efficient photocatalytic CO₂ reduction catalysts.