Modulating the Schottky barrier of Pt/PbTiO₃ for efficient piezo-photocatalytic hydrogen evolution

Charge recombination severely restricts the photocatalytic efficiencies of materials. Loading cocatalysts on the surface of host photocatalysts is a promising strategy for charge separation, which, however, suffers from the large Schottky barrier at the cocatalyst/host interface. Herein, a series of Pt/PbTiO₃ compounds were constructed as a proof-of-concept utilizing the piezoelectric field of PbTiO₃ under acoustic vibrations to modulate the height of the interfacial Schottky barrier. These hybrid systems achieved highly efficient piezo-photocatalytic H₂ evolution under simultaneous ultrasonication and light illumination. The manipulation of the height of the Schottky barrier by the piezoelectric effect was validated by the I-V characteristics collected from conductive AFM. It is proposed that the acoustic-wave-induced piezoelectric field increased the electron flow from PbTiO₃ to Pt over the modulated Schottky barrier, which promoted the spatial separation of photo-generated charge carriers and consequently enhanced the H₂ evolution. These findings will extend the fundamental understanding of the synergistic piezo-photocatalysis mechanism and provide a new opportunity toward the rational design of novel materials systems for clean energy conversion.