Facet-dependent spatial separation of dual cocatalysts on MOF photocatalysts for H2O2 production coupling biomass oxidation with enhanced performance

Cooperative coupling of photocatalytic two-electron oxygen reduction reaction (2e-ORR) with oxidative organic synthesis holds great promise for sustainable production of valuable chemicals. To achieve high performance, the rational design of photocatalysts with effective electron-hole separation and redox capability is crucial. Herein, a MOF-based photocatalyst with crystal facet-dependent spatial separation of dual cocatalysts is constructed for photocatalytic 2e-ORR coupled with vanillyl alcohol oxidation reaction (VAOR). The facet-dependent growth of reductive Pd and oxidative CoO x cocatalysts respectively on the {100} and {001} facets of MIL-125-NH 2 enables the directional migration of photogenerated carries, facilitating the charge separation for redox reactions. Additionally, the interaction between Pd and MIL-125-NH 2 modulates the Pd sites into electron-sufficient state with upshifted d-band center, promoting the O 2 activation and *OOH intermediate formation. The rationally designed composite photocatalyst delivers an excellent H 2 O 2 yield of 74.8 mM g −1 h −1 and a high vanillic acid production rate of 80.9 mM h −1 g −1 with the conversion and selectivity of 96.8 % and 91.1 %, respectively. • MOF-based photocatalysts with facet-dependent spatial separation of cocatalysts. • Directional migration of photogenerated carries facilitate the charge separation. • Coupling photocatalysis of H 2 O 2 production and vanillyl alcohol oxidation reaction. • Remarkable H 2 O 2 and vanillic acid yields of 74.8 and 80.9 mM h −1 g −1 , respectively.