Enhanced photocatalytic hydrogen generation efficiency through molybdenum-sulfur dual sites synergistic catalysis

Photocatalysis has gained significant attention in recent years for water splitting, with graphitic carbon nitride (g-C3N4) emerging as a promising candidate. However, the low carrier mobility and the lack of active sites for hydrogen evolution limit photocatalytic hydrogen evolution performance. Herein, this work presents a facile approach to achieve single Mo sites with a unique local coordination structure featuring one Mo atom coordinated with two nitrogen atoms and one sulfur atom. Among the prepared photocatalysts, 6 wt% Mo/SCN exhibits the highest photocatalytic hydrogen evolution activity with a yield rate of 4.05 mmol g-1 h-1, which is 13 times higher than that of pure g-C3N4 and superior to most of the g-C3N4 series photocatalysts. Experimental results and density functional theory calculations confirm that the Mo single-atom and S atom have synergistic catalysis under the co-modification, and the formed Mo-S bonds will enhance the ability of the substrate to anchor the Mo single-atom to enhance the stability of the photocatalyst. This work offers insights into transition metal single-atom and synergistic catalysis design for photocatalytic hydrogen evolution.