Metallic Bi self-deposited BiOCl promoted piezocatalytic removal of carbamazepine

Development of high-performance piezocatalyst has attracted much attention for efficiently piezocatalytical removal of pharmaceuticals and personal care products in the wastewater. In this work, metallic Bi nanoparticles were successfully self-deposited on the surface of piezocatalyst BiOCl via an in-situ reduction method to modify the piezoelectric response for the piezocatalytic degradation of carbamazepine (CBZ). The present of Bi nanoparticles significantly enhanced piezocatalytic performance of BiOCl , in which 75.11% of CBZ (5 mg/L) was removed under ultrasonic vibration in the presence of Bi/BiOCl-50 (0.5 g/L) after 30 min, being 52.72% higher than that of pure BiOCl. Through scavenger test, electron paramagnetic resonance detection and electrochemical analysis , the enhanced piezocatalytic activity was due to that Bi nanoparticles improved the separation efficiency of piezoelectric charges to generate more reactive oxygen species. The stability of the piezocatalyst, effects of reaction parameters, treatment performance of real wastewater , and the possible pathways of CBZ degradation were systematically investigated. The work provides a deep understanding on the piezocatalytic process and brings a new track to enhance the piezocatalytic performance for Bi-based piezoelectric materials without introducing any impurities in water purification .