Hierarchical Nanostructured BiVO4/Bi4V2O10 Heterojunctions for Piezocatalytic Degradation of Organic Dyes

This work was designed to show the application of BiVO4/Bi4V2O10 nanostructured heterojunction composites in piezocatalysis. The BiVO4/Bi4V2O10 composites prepared by a solvothermal method realized dye degradation via utilizing vibration energy. Various factors affecting the piezocatalytic property of the composite catalyst were investigated. The highest rhodamine B (RhB) degradation rate of 99.3% was achieved after 45 min of ultrasonic vibration on the BiVO4/Bi4V2O10 composite catalyst prepared with 3 h of solvothermal time at 140 °C. The structure, morphology, and optical property of the as-prepared catalysts were extensively characterized. The good piezocatalytic activity of the composite was ascribed to the hierarchical morphology of the nanoporous sphere coated with nanoflakes, and the formation of a heterojunction structure between BiVO4 and Bi4V2O10, which effectively separated the ultrasound-induced electron–hole pairs and suppressed their recombination. Based on the band potentials of BiVO4 and Bi4V2O10, a plausible mechanism for piezocatalytic dye degradation was proposed, which was confirmed by the quenching effect of various radical scavengers. This work demonstrates the potential use of BiVO4/Bi4V2O10 nanocomposites in piezocatalytic applications and provides valuable insights into the design and preparation of piezocatalysts for water purification.