Synthesis of nanosized Ag-modified 2D/2D hydroxylated g-C3N4/TS-1 Z-scheme nanocomposites for efficient photocatalytic CO2 reduction

Abstract It is significant to enhance the charge separation and extend the visible-light range for the TS-1 molecular sieve-based photocatalysts to improve the photocatalytic performance for CO2 reduction reaction (CO2RR). Here, dimension-matched 2D/2D hydroxylated g-C3N4/TS-1 (hCN/TS-1) nanocomposites have been successfully fabricated and further modified by nanosized Ag by the photoreduction method. The optimum Ag-modified hCN/TS-1 exhibits ∼ 7-time CO2 conversion than that of 2D TS-1. Based on the surface photovoltage responses, monochromatic photocurrent action spectra and electrochemical reduction curves, it is confirmed that the exceptional photoactivity is attributed to the greatly-enhanced charge separation via the Z-scheme mode between hCN and TS-1 at intimately-connected interfaces, extended visible-light absorption endowed by hCN, and Ag nanoparticles as the effective electron capturers with favorable catalytic function for activating CO2 molecules. This work showcases an effective and feasible design strategy to fabricate highly effective TS-1 molecular sieve-based photocatalysts for practical application.