Synergistic electron bridge and heterojunction engineering for boosted charge transfer toward high-efficiency hydrogen evolution

Abstract

Hydrogen-substituted graphdiyne (H-GDY) possesses an extensively π-conjugated framework coupled with exceptional charge transport capabilities. Monocomponent photocatalytic systems, however, face inherent limitations in hydrogen production efficiency due to accelerated charge recombination kinetics and suboptimal catalytic site density. In this study, a Z-scheme heterojunction photocatalytic system with an electron-bridge (CoP), denoted as CoTiO₃/CoP/H-GDY, was successfully constructed to facilitate spatial separation and directional migration of photogenerated carriers, achieving efficient photocatalytic hydrogen production. The electron-bridge serves as a charge-transfer interface facilitator in the Z-scheme architecture, not only reducing interface resistance between CoTiO₃ and H-GDY but also preserving the strong redox potentials of photogenerated carriers. This work elucidates the synergistic mechanism between transition metal phosphide electron-bridges and heterojunction structures, providing fundamental guidance for developing advanced photocatalytic materials.