Optimizing Oxygen and Intermediate HOO^* Adsorption of Cu–Pd Alloy Cocatalyst for Boosting Photocatalytic H₂O₂ Production of BiVO₄

Abstract The modification of Pd cocatalysts is considered to be an effective strategy to improve H₂O₂ production of photocatalysts because it can accelerate the reaction rate of O₂ reduction. However, the strong adsorption between O₂ molecules and Pd atoms is not conducive to the formation of intermediate HOO^* and leads to the further reduction of H₂O₂ to H₂O, thus limiting the improvement of H₂O₂ production. To solve the issue, in this work, Cu–Pd alloy cocatalysts are selectively modified on the electron‐rich facets of BiVO₄ via facile photoinduced deposition and subsequent galvanic displacement. DFT calculations indicate that the incorporation of Cu atoms to Pd atoms weakens the oxygen adsorption energy and HOO^* binding energy on Pd atom surfaces, thus increasing the activity and selectivity of O₂ reduction to H₂O₂. Further experimental results show that the optimized Cu‐Pd/BiVO₄(5:1) photocatalyst exhibits markedly boosted activity for H₂O₂ production (2189 µmol L^‐1), which is 3.2‐fold higher than that of BiVO₄ with modification of 0.3 wt% Pd cocatalyst (675 µmol L^‐1). Additionally, the incorporation of metal Cu enables the economic utilization of Pd atoms and reduces the expense of the Pd cocatalyst.