Interfacial Acid Sites‐Mediated ZnO‐Based Electrocatalysts for Sustainable Dual‐Pathway H ₂ O ₂ Production and Rechargeable Zn‐H ₂ O ₂ Electrochemical Cell

Abstract

ABSTRACT Facing the challenge of achieving efficient and sustainable hydrogen peroxide (H 2 O 2 ) production, a promising strategy is developing highly selective electrocatalysts with controllable synthesis, structural design and performance optimization. Herein, an interfacial acid sites‐mediated ZnSe/ZnO heterojunction is synthesized for highly selective two‐electron oxygen reduction reaction (ORR) toward H 2 O 2 production. Experimental and theoretical results reveal that surface selenization induced reconstruction, forming a synergistic interface with a built‐in electric field and tailored oxygen vacancies (Ovs), which collaboratively optimize the electronic structure and accelerate reaction kinetics of two‐electron ORR. Moreover, interfacial unsaturated Zn 2+ sites and OVs served as Lewis acids sites to enhance O 2 adsorption and activation, while Br ø nsted acids sites were liable to donate protons to promote *OOH formation. Consequently, a ZnSe/ZnO ‖ ZnO flow cell enabled paired electrolysis for concurrent H 2 O 2 production with a high H 2 O 2 yield of 754.4 M g cat −1 over 12 h. A rechargeable Zn‐H 2 O 2 cell using ZnSe/ZnO cathode delivered a power density of 11.99 mW cm −2 as a self‐sustaining process for simultaneous on‐site H 2 O 2 production and electrical energy generation. This work offers a sustainable route for on‐site H 2 O 2 synthesis with improved energy efficiency, advancing green chemistry and circular economy.