Structurally disordered MoSe₂ with rich 1T phase as a universal platform for enhanced photocatalytic hydrogen...

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 MoSe₂ with abundant 1T phase as a versatile cocatalyst for photocatalytic hydrogen evolution. Using MoSe₂/carbon nitride (CN) hybrids as a case study, it is demonstrated that amorphous MoSe₂ significantly enhances the hydrogen evolution rate of CN, achieving up to 11.37 μmol h^-1, surpassing both low crystallinity (8.24 μmol h^-1) and high crystallinity MoSe₂ (3.86 μmol h^-1). Experimental analysis indicates that the disordered structure of amorphous MoSe₂, 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, TiO₂, and ZnIn₂S₄, thereby offering novel insights into the advancement of high-performance non-precious catalysts through phase engineering.