Piezotronics enhanced photocatalytic activities of Ag-BaTiO3 plasmonic photocatalysts

Ag-BaTiO₃ piezo-photocatalysts were fabricated by precipitating Ag nanoparticles on BaTiO₃ nano-piezoelectric through a photochemical reducing approach. The mechanism of piezo-photocatalysis and the effect of the size and distribution of Ag nanoparticles on the properties of the photocatalyst were investigated. The surface plasmon resonance (SPR) of Ag nanoparticles endows the catalyst an absorption in the visible light region. The piezoelectric field originated from the deformation of BaTiO₃ can further enhance the separation of the photogenerated carriers of SPR and promote the formation of oxidizing radicals that could accelerate the degradation of organic dyes. The 1mAg-BaTiO₃ showed an excellent photocatalytic performance of degrading 83% Rh B in 75 min under full-spectrum light irradiation with ultrasonic excitation. The piezoelectric charges on the surfaces of the BaTiO₃ and formed piezoelectric potential in the nanocrystal have been confirmed to express an increment of the catalytic activity more than 20% (compared with the sole photocatalysis). This work provides an effective technology for environment purification and could be extended to other piezoelectric materials.