Synergistic effect of phosphorus doping and MoS2 co-catalysts on g-C3N4 photocatalysts for enhanced solar water splitting

Abstract

Carbon nitride (g-C3N4) is a promising metal-free and visible-light-responsive photocatalyst. However, its photocatalytic efficiency still suffers from high recombination rates of photoinduced charge carriers, slow kinetics of surface redox reactions, and relatively poor light absorption. Herein, a non-noble metal photocatalyst of MoS2 nanodots anchored on P-doped g-C3N4 via in situ photodeposition was constructed. With the synergetic effect of the P-doping and MoS2 co-catalyst, the as-prepared P-doped g-C3N4/MoS2 catalyst has achieved efficient photocatalytic overall water splitting with a hydrogen evolution rate of 121.7 μmol h−1 g−1. Experimental results and Density functional theory (DFT) simulations indicate that the enhanced photo-absorption capacity originates from the reduced band gaps by P doping. Meanwhile, the MoS2 reduces the overpotential of the water oxidation process and improves hydrogen adsorption capability in the hydrogen evolution reaction. This work can pave a new avenue to design and develop noble-metal-free water-splitting photocatalysts for future large-scale applications.