Enhancement in the photocatalytic activity of carbon nitride through hybridization with light-sensitive AgCl for carbon dioxide reduction to methane

The production of carbon-neutral CH4 solar fuel from CO2 using a photocatalyst is an ideal future energy source to combat energy crisis and global warming concomitantly. In this contribution, effective photocatalytic reduction of CO2 using a silver chloride (AgCl)/carbon nitride (CN) hybrid was demonstrated. The urea-derived CN was initially protonated to improve the subsequent dispersibility and anchorage of the AgCl particles. The nucleation process of AgCl was successively carried out by an in situ deposition-precipitation approach. The as-prepared AgCl/CN photocatalyst at an optimized loading exhibited a much higher visible-light photoactivity, giving an up to 2.5-fold enhancement in comparison to pure CN. This enhanced photocatalytic activity is attributed to enhanced light absorption provided by the surface plasmon resonance (SPR) of Ag-0 which was simultaneously reduced during the photocatalytic reaction and the hierarchical heterojunction system which favourably inhibits electron-hole recombination.