0D/2D heterojunction photocatalysts for improved full-spectrum-light-driven hydrogen evolution

Abstract

Enhancing the full-spectrum light-driven hydrogen evolution of water splitting continues to be a pivotal challenge in the pursuit of advanced photocatalysts. In this study, the instability of MXene under light illumination has been effectively countered by affixing ultra-minor nanoparticles ZnO quantum dots (QDs) onto the surface of the two-dimensional (2D) MXene substrate. This process ensures the high electronic conductivity of MXene, thereby enhancing its photocatalytic stability and maintaining hydrogen production efficiency. The loading of a small amount of ZnO QDs enables MXene to realize a 10-fold improvement under full-spectrum excitation. Combined with density functional theory (DFT) calculations, the results confirm that such excellent photocatalytic performance is mainly attributed to the increase of reactive active sites for hydrogen-extraction reaction (HER) on the surface of MXene, the fast carrier migration at the interface of heterostructure, and the improvement of the electron–hole pairs separation, thus resulting in the efficient full-spectrum solar catalytic activity and kinetic processes.