Polarized N ⁺ ‐Mediated Charge‐Transfer State Drives Two‐Electron Water Oxidation

Abstract

Abstract Achieving selective two‐electron water oxidation (2e − WOR) for sustainable hydrogen peroxide (H 2 O 2) synthesis, while suppressing the competing four‐electron oxygen evolution (4e − OER), represents a formidable challenge in artificial photosynthesis. The difficulty lies in the inherent vulnerability of the *OOH intermediate to over‐oxidation or disproportionation, which triggers uncontrollable chain side reactions and naturally biases the reaction toward the less selective 4e − OER pathway. Here, we present a surface‐engineering strategy utilizing a ZnCdS 2 photocatalyst functionalized with polarized N⁺ surfactants, enabling molecular‐level control over interfacial water oxidation pathways by establishing a charge‐transfer (C‐T) excited state. The polarized N⁺ centers effectively reconfigure the surface electronic states through molecular‐scale polarization, achieving i) precise modulation of hole potentials and ii) stabilization of the *OOH intermediate, thereby promoting a direct 2e − WOR pathway. Without the use of any sacrificial reagents, this design achieves an exceptional H 2 O 2 production rate of 2.37 mmol·g − 1 ·h − 1 (20.26 times of pristine ZnCdS 2 ) statically and the scalable outlet concentration of 1.61 mM through a serial micro‐batch flow reactor. By bridging atomic‐level charge control with macroscopic catalytic performance, our work offers a proof‐of‐concept advance in C‐T excited state driven photocatalysis, highlighting how surface electronic states can drive selective multi‐electron reactions.