Built-In Electric Field-Driven Charge Separation in Nanocage Co3O4/ZnCdSe Heterojunctions for Photocatalytic Hydrogen Evolution

Abstract

Inefficient charge separation limits the photocatalytic performance of ZnCdSe. Herein, a nanoscale Co3O4/ZnCdSe heterojunction is constructed by coupling MOF-derived Co3O4 hollow nanocages with ZnCdSe nanoparticles. The hollow nanocage structure enhances light harvesting and charge migration, enabling the optimized ZC-5 composite to achieve an H2 evolution amount of 766.10 μmol within 4 h, which is 7.4× higher than that of pristine ZnCdSe. XPS, in situ XPS, and work-function calculations reveal that interfacial charge redistribution induces a built-in electric field, promoting directional electron transfer and charge separation. This work provides a viable strategy for developing efficient photocatalysts for solar hydrogen production.