Structurally disordered MoSe with rich 1T phase as a universal platform for enhanced photocatalytic hydrogen production.

The improvement of surface reactivity in noble-metal-free cocatalysts is crucial for the development of efficient and cost-effective photocatalytic systems. However, the influence of crystallinity on catalytic efficacy has received limited attention. Herein, we report the utilization of structurally disordered MoSe with abundant 1T phase as a versatile cocatalyst for photocatalytic hydrogen evolution. Using MoSe/carbon nitride (CN) hybrids as a case study, it is demonstrated that amorphous MoSe significantly enhances the hydrogen evolution rate of CN, achieving up to 11.37 μmol h, surpassing both low crystallinity (8.24 μmol h) and high crystallinity MoSe (3.86 μmol h). Experimental analysis indicates that the disordered structure of amorphous MoSe, characterized by coordination-unsaturated surface sites and a rich 1T phase with abundant active sites at the basal plane, predominantly facilitates the conversion of surface-bound protons to hydrogen. Conversely, the heightened charge transfer capacity of the highly crystalline counterpart plays a minor role in enhancing practical catalytic performance. This approach is applicable for enhancing the photocatalytic hydrogen evolution performance of various semiconducting photocatalysts, including CdS, TiO, and ZnInS, thereby offering novel insights into the advancement of high-performance non-precious catalysts through phase engineering.