Synergistic ZnMn2O4/Cu3P coupling via a Type-II p-n heterojunction for enhanced charge separation and photocatalytic hydrogen evolution

The development of efficient and sustainable photocatalysts for solar-driven hydrogen production is vital for advancing clean energy technologies. In this work, a ZnMn 2 O 4 /Cu 3 P heterojunction photocatalyst is reported for the first time. The ZnMn 2 O 4 (ZMO) component was synthesized through a simple room-temperature route, offering an energy-efficient and environmentally friendly approach using earth-abundant materials. The optimized 5 wt% Cu 3 P with ZMO composite achieved a hydrogen evolution rate of 1191 μmol h −1 g −1 under direct sunlight, which showed a 6-fold increase over that of pristine ZMO. The enhancement in photocatalytic performance is attributed to the synergistic interaction between ZMO (the primary light absorber) and Cu 3 P (an electron-accepting cocatalyst). The formation of a p-n heterojunction with a type-II band alignment facilitates effective charge separation and transfer by suppressing charge-carrier recombination. Furthermore, the photocatalyst exhibited good stability and recyclability during repeated usage. These findings demonstrate a simple, low-cost, and sustainable strategy for developing high-performance photocatalysts for solar hydrogen generation.