 vast majority of photocatalysts for hydrogen production relies on additional sacrificial agents and noble metal co-catalysts. It is of great importance yet challenging to achieve photocatalytic overall water splitting with decent performance. Here, the authors report Ni2P-based photocatalyst assisted by H202, cracking reaction for overall water splitting with H202 production of 1507 mol H1G1H2 and 702 mol H1G1.