A coupled photo-piezo-catalytic effect in a BST-PDMS porous foam for enhanced dye wastewater degradation

Over the last decade, ferro-/piezo-electric materials have provided new directions to improve catalysis. However, current challenges that must be solved include secondary pollution by the piezoelectric particulates and a limited potential for reuse and recyclability. Here, we report an efficient approach of using a piezoceramic-polymer porous foam to package barium strontium titanate (BST) particulates and prevent secondary pollution, while being able to maintain a high photo-piezo-catalytic performance after 10 cycles of repeated catalytic reactions. The photo-piezo-catalysis achieves a 97.8% dye degradation and an enhanced performance of 275% when compared to individual photocatalysis by light irradiation or periodic low-frequency mechanical squeezing alone. It is suggested the photo-piezo-catalytic coupling effect combines the advantages of increased generated electron-hole pairs and the induced piezoelectric electric field leads to a higher degree of electron-hole separation. The BST-PDMS porous foam for photo-piezo-catalysis offers a potential approach in wastewater degradation via utilizing both solar energy and environmental mechanical sources.