Giant Charge Separation-Driving Force Together with Ultrafluent Charge Transfer in TiO₂/ZnFe-LDH Photoelectrode via Ferroelectric Interface Engineering

Abstract

Hydrogen fuel production using photoelectrochemical (PEC) water-splitting technology is incredibly noteworthy as it provides a sustainable and clean method to alleviate the energy environmental crisis. A highly rapid electron shuttle at the semiconductor/WOC (water oxidation cocatalyst) interface is vital to improve the bulk charge transfer and surface reaction kinetics of the photoelectrode in the PEC water-splitting system. Yet, the inevitably inferior interface transition tends to plague the performance enhancement on account of the collision of hole− electron transport across the semi/cat interface. Herein, we address these critical challenges via inserting ferroelectric layer BTO (BaTiO 3 ) into the semi/cat interface. The embedded polarization electric field induced by ferroelectric BTO remarkably pumped hole transfer at the semiconductor/WOC (TiO 2 /ZnFe-LDH) interface and selectively tailored the electronic structure of LDH surface-active sites, leading to overwhelmingly improved surface hole transfer kinetics at LDH/electrolyte interface, which minish the electron−hole recombination in bulk and on the surface of TiO 2 . The TiO 2 nanorods encapsulated by ferroelectric-assisted ZnFe-LDH achieve 105% charge separation efficiency improvement and 53.8% charge injection efficiency enhancement compared with pure TiO 2 . This finding offers a strategic design for electrocatalytic-assisted photoelectrode systems by ferroelectric-pumped charge extraction and transfer at the semiconductor/WOC interface.