Remarkably enhanced photocatalytic performance of Au/AgNbO3 heterostructures by coupling piezotronic with plasmonic effects

Both localized surface plasmon resonance (SPR) effect in noble metal nanostructures and piezotronic effect in piezoelectric semiconductors have been proven to be effective in improving photocatalytic performance. In this work, we report a novel heterostructured piezo-photocatalyst by decorating plasmonic Au nanoparticles (AuNPs) on piezoelectric AgNbO3 nanocubes. The optimized Au/AgNbO3 nanocomposites exhibit significantly enhanced photocatalytic activities toward hydrogen evolution reaction from water (392 μmol g−1 h−1) and degradation of organic pollutants (first-order rate constant of 0.054 min−1 for RhB) assisted by ultrasonic mechanical vibration (110 W, 40 kHz), which are about 2.2- and 5.7-times that of under only light irradiation, respectively. The considerably promoted photocatalytic activity can be attributed to a synergetic coupling of SPR and piezotronic effect, by which energetic hot electrons generated on the plasmonic AuNPs can be effective extracted onto AgNbO3 driven by mechanical vibration induced piezo-potential near the heterojunction. This work undoubtedly demonstrates that the integration of SPR and piezotronic effects holds great promise to improve the photocatalytic efficiencies.