Enhanced photocatalytic overall water splitting via non-precious Zn-induced spatial separation of photoexcited excitons in polymeric carbon nitride

Photocatalytic water splitting has emerged as a vital technology for producing clean hydrogen fuel, addressing global energy needs. However, most research has focused on half-water splitting with sacrificial agents, which limits its practical application in fuel production. In this study, we present an advanced co-catalyst system for polymeric carbon nitride (CN) designed for efficient overall water splitting, a crucial step toward scalable hydrogen fuel generation. The co-catalyst system includes full loading of CoO x , Zn-Pt, and Cr 2 O 3 , with Zn strategically inserted between Pt and CN. This configuration enhances the spatial separation of photoexcited carriers, promoting efficient segregation of oxidation and reduction sites while minimizing electron-hole recombination. The optimized system achieves a stoichiometric H 2 and O 2 ratio of 2:1, with a hydrogen evolution rate that is nine times higher than when Pt alone is used as the co-catalyst. This advancement provides a pathway for efficient solar-driven hydrogen production, addressing the critical challenge of moving beyond half-water splitting and contributing to the development of clean fuel technologies.