Ferroelectric polarization enabled spatially selective adsorption of redox mediators to promote Z-scheme photocatalytic overall water splitting

Although the artificial Z-scheme system, mimicking natural photosynthesis, has shown promising applications in photocatalytic water splitting, it often suffers from the side reaction of redox mediator, which considerably undermines the efficacy of photocarrier utilizations. Herein, we propose to suppress the side reaction by using ferroelectric polarization, which not only provides a strong driving force to spatially separate photocarriers to the oppositely poled surface but also induces spatially selective adsorption of redox ions. Single-domain ferroelectric PbTiO3 nanoplates have been adopted as a model ferroelectric to construct the Z-scheme system with BiVO4 particles and a cationic redox mediator. In contrast to the inactive multi-domain ferroelectric PbTiO3-based system, the so-formed Z-scheme system delivers stable high activity for photocatalytic overall water splitting under both visible light and simulated solar insolation. This work offers a proof of concept to realize efficient solar photocatalytic water splitting based on single-domain ferroelectric Z-scheme system.