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

Abstract

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.