Piezotronic Effect Enhanced Plasmonic Photocatalysis by AuNPs/BaTiO3 Heterostructures

Piezopotential-assisted catalysis is of great significance for low cost and efficient catalysis processes. Here, Au-x/BaTiO3 plasmonic photocatalysts are fabricated by precipitating Au nanoparticles on piezoelectric BaTiO3 nanocubes through a chemical approach. The Au nanoparticles (<8 nm) are decorated uniformly on the surface of BaTiO3, which endows the heterostructure with a wide light absorption from 300 to 600 nm. The photocatalytic properties of the heterostructures are investigated in detail toward methyl orange (MO) degradation. The Au content, piezoelectric potential of the BaTiO3 substrate, and surface plasmon resonance (SPR) are confirmed to be vital to the photocatalytic activity. The Au-4/BaTiO3 shows an optimum photocatalytic performance for a complete degradation of MO in 75 min under full spectrum light irradiation with auxiliary ultrasonic excitation. The piezoelectric field originating from the deformation of BaTiO3 further enhances the separation of photon-generated carriers induced by SPR and promotes the formation of hydroxyl radicals, which results in a strong oxidizing ability of organic dyes. This work introduces the piezotronic effect to enhance plasmonic photocatalysis with Au-x/BaTiO3 heterostructures, which is ready to extend to other catalytic systems and offers a new option to design high-performance catalysts for pollutant treatment.