Hollow AgPt@Pt core-shell cocatalyst with electron-rich Pt− shell for boosting selectivity of photocatalytic H2O2 production for faceted BiVO4

Platinum (Pt) is an excellent oxygen reduction cocatalyst with great potential for the photocatalytic production of H 2 O 2 . However, its catalytic efficiency is limited by the strong adsorption of O 2 , which facilitates O–O bond cleavage and reduces selectivity for the 2-electron oxygen reduction reaction (ORR). Fortunately, the strength of the Pt–O bond can be weakened by adjusting the structure of the cocatalyst to modify the electronic structure of Pt. In this paper, Pt and Ag cocatalysts are successively modified on the (010) facet of BiVO 4 through a two-step photodeposition method. Due to the occurrence of a displacement reaction during the process, a synergistic catalyst with a hollow AgPt alloy core and an electron-rich Pt δ − shell (AgPt@Pt) structure is ultimately synthesized. Photocatalytic experiments demonstrated that the H 2 O 2 production from BiVO 4 modified with hollow AgPt@Pt reached an impressive 1021.5 ​μmol ​L −1 . This corresponds to an AQE of 5.1%, which is 28.6 times higher than that of the Pt/BiVO 4 photocatalyst with only 35.7 ​μmol ​L −1 . Furthermore, research results show that AgPt can transfer electrons to the Pt shell to generate electron-rich Pt δ − active sites, thus increasing the antibonding orbital occupancy of Pt–O ads in AgPt@Pt catalysts. This electron redistribution weakens the adsorption strength of O 2 on Pt, promoting the 2-electron ORR and facilitating the efficient generation of H 2 O 2 . This synthesis strategy offers a versatile approach for preparing other Pt-based nano-alloy cocatalysts with improved activity for the selective reduction of O 2 to H 2 O 2 . The adsorption ability of O 2 and OOH∗ on the Pt site can be enhanced to improve photocatalytic H 2 O 2 production by constructing an electron-rich Pt δ − site. • AgPt@Pt nanoparticles were prepared by photo-induced continuous reduction method. • The charge spontaneously transfers to produce the electron-rich Pt δ − active site. • Pt δ − nanoparticles spontaneously enhance the intensity of O 2 adsorption. • The BiVO 4 /AgPt@Pt (1:1) exhibits high photocatalytic H 2 O 2 -production activity.