Suppressing Charge Screening via Z‐Scheme With Polarization Field for In Situ H ₂ O ₂ Generation and Utilization

Abstract

ABSTRACT Piezoelectric polarization in n‐type semiconductors provides a sustainable pathway for hydrogen peroxide (H 2 O 2 ) production. However, its efficiency is fundamentally constrained by the piezoelectric screening effect, whereby accumulated free carriers rapidly neutralize polarization‐induced charges, leading to short‐lived internal fields and suppressed redox activity. Herein, ZnO nanoparticles are electrostatically integrated with a Zr‐based metal–organic layer to construct a ZnO/Zr‐MOL Z‐scheme heterojunction that intrinsically mitigates this screening limitation. Interfacial coupling enables polarization‐regulated band bending, spatially separating piezo‐generated electrons and holes, and preventing their premature compensation by mobile carriers. The Z‐scheme configuration preserves strong redox potentials while suppressing bulk and interfacial recombination, and the polarization‐driven charge redistribution and dynamic realignment of the conduction and valence bands sustain the piezoelectric potential and markedly enhance carrier mobility and lifetime. Consequently, the optimized ZnO/Zr‐MOL catalyst achieves an H 2 O 2 production rate of 13.21 m m g −1 h −1 in pure water under ambient air conditions. When incorporated into an autonomous tidal‐driven reactor, the heterostructure demonstrates strong environmental adaptability, achieving 74.5% degradation of Rhodamine B in 5 L of wastewater within 180 min. This study provides a fundamental strategy to overcome piezoelectric screening and establishes a mechanistic framework for polarization‐assisted charge transfer in heterostructure systems.