Sonochemical Engineering of Atomic Pb─O─Zn Bridges for Robust Z‐Scheme Overall Pure Water Splitting

ABSTRACT Efficient photocatalytic overall water splitting is often constrained by the fundamental trade‐off between charge separation efficiency and redox driving force in conventional heterojunctions. Direct Z‐scheme architectures theoretically resolve this dilemma, yet constructing robust, defect‐free interfaces remains a formidable synthetic challenge. Here, we introduce a sonochemical strategy in which transient cavitation drives the in situ insertion of Zn during the growth of In 2 S 3 on PbTiO 3 , giving rise to interfacial Pb─O─Zn bridges. These Zn bridges convert the junction from type‐II to a direct Z‐scheme, enabling selective interfacial recombination while preserving high oxidation and reduction potentials. Multimodal spectroscopic and density functional theory confirmed the Z‐scheme pathway and prolonged carrier lifetimes. The resulting photocatalyst delivers stoichiometric H 2 and O 2 evolution rates of 166.6 and 81.7 µmol h − 1 , demonstrating a competitive performance within reported Z‐scheme heterostructure‐based photocatalysts. This transient cavitation‐driven heteroatom insertion strategy provides a potentially general and programmable protocol for engineering precise semiconductor interfaces and constructing direct Z‐scheme junctions for solar fuel production.