In-plane heterostructured Ag₂S-In₂S₃ atomic layers enabling boosted CO₂ photoreduction into CH₄

Sluggish separation and migration kinetics of the photogenerated carriers account for the low-efficiency of CO₂ photoreduction into CH₄. Design and construction two-dimensional (2D) in-plane heterostructures demonstrate to be an appealing approach to address above obstacles. Herein, we fabricate 2D in-plane heterostructured Ag₂S-In₂S₃ atomic layers via an ion-exchange strategy. Photoluminescence spectra, time-resolved photoluminescence spectra, and photoelectrochemical measurements firmly affirm the optimized carrier dynamics of the In₂S₃ atomic layers after the introduction of in-plane heterostructure. In-situ Fourier transform infrared spectroscopy spectra and density functional theory (DFT) calculations disclose the in-plane heterostructure contributes to CO₂ activation and modulates the adsorption strength of CO* intermediates to facilitate the formation of CHO* intermediates, which are further protonated to CH₄. In consequence, the in-plane heterostructure achieves the CH₄ evolution rate of 20 μmol·g^-1·h^-1, about 16.7 times higher than that of the In₂S₃ atomic layers. In short, this work proves construction of in-plane heterostructures as a promising method for obtaining high-efficiency CO₂-to-CH₄ photoconversion properties.