Enhancing the piezo-photocatalytic tetracycline degradation activity of BiOBr by the decoration of AuPt alloy nanoparaticles: Degradation pathways and mechanism investigation

AuPt alloy nanoparaticles were successfully decorated on the BiOBr surface to form AuPt/BiOBr piezophotocatalysts via a photoreduction route. The removal of organic dyes (acid orange 10 (AO10) and rhodamine B (RhB)) were selected to estimate the photocatalytic activity of samples under simulated sunlight irradiation, which reveals that the AuPt/BiOBr composite manifests remarkably enhanced photocatalytic degradation ability compared with Au/BiOBr, Pt/BiOBr and bare BiOBr. Notably, the piezo-photocatalytic removal activity of AuPt/BiOBr towards the degradation of tetracycline (TC) was evaluated under the simulated sunlight and ultrasound irradiation. It is found that the piezo-photocatalytic removal performance of AuPt/ BiOBr is obviously super to its individual piezoand photocatalytic results, and its piezo-photocatalytic efficiency of TC increased by -33.6% and -53.3% in comparison to corresponding photocatalytic and piezocatalytic degradation efficiency. The piezo-photocatalytic degradation pathway of TC was systematacially discussed and proposed. The built-in electric field caused by the piezoelectric effect of AuPt/BiOBr sample significantly accelerate the bulk migration and separation of induced charges. On the other hand, the surface plasmonic resonance (SPR) effect of AuPt alloy nanoparaticles provided more hot electrons for piezo-photocatalytic reaction, meanwhile the AuPt alloy nanoparticles also promote the surface migration of induced charges on the AuPt/ BiOBr sample.

Automated summary

AuPt/BiOBr composite with AuPt alloy nanoparaticles decorated on BiOBr surface was prepared via photoreduction. It showed significantly enhanced photocatalytic degradation ability compared with Au/BiOBr, Pt/BiOBr, and bare BiOBr. The piezo-photocatalytic removal activity of AuPt/BiOBr towards tetracycline (TC) degradation was evaluated under simulated sunlight and ultrasound irradiation, and exhibited superior performance to individual piezo and photocatalytic results.