A Synchronous d–p Hybridization and Protonated State Regulation Strategy for Efficient H₂O₂ Photosynthesis through Optimized Water Oxidation

Photocatalytic H 2 O 2 synthesis with Fe‐based cocatalysts is sustainable but limited by sluggish water oxidation reaction (WOR) kinetics and low selectivity from weak *OH intermediate adsorption and instability. To address this, a “Fe–O–P d – p hybridization synergistic protonated state regulation” strategy is devised to enhance the WOR rate and H 2 O 2 selectivity. A dual‐cocatalyst FeOOH/BiVO 4 /Au, synthesized via two‐step photodeposition, optimizes active sites and suppress charge recombination, with Au as oxygen reduction reaction active sites while FeOOH as WOR active sites. Subsequent phosphoric acid impregnation generates H 2 PO 4 − @FeOOH/BiVO 4 /Au, wherein Fe–O–P d – p hybridization modulates *OH adsorption and protonation state regulation enhances selectivity toward the two‐electron WOR pathway. The optimized H 2 PO 4 − @FeOOH(1%)/BiVO 4 /Au(3%) catalyst achieved a high H 2 O 2 yield of 2321 μmol L −1 in 3 h, 6 times higher than FeOOH/BiVO 4 /Au, and the best among reported Bi‐based photocatalysts under pure water. Density functional theory and in situ Fourier transform infrared spectroscopy showed that Fe–O–P hybridization raises the Fe d‐band center and strengthens *OH adsorption, accelerating electron transfer during WOR. This work offers a new design concept for efficient WOR cocatalysts to boost photocatalytic H 2 O 2 production.