Piezo-photocatalysis boosted by flexible inorganic-organic hybrid piezoelectric porous sponge

Fabricating built-in electric fields provides a practical solution for the separation of photogenerated electrons and holes, whose recombination usually restricts the elevation of photocatalytic performance. In this work, a flexible PbTiO 3 (PTO)-polyvinylidene fluoride (PVDF) inorganic-organic hybrid piezoelectric photocatalytic sponge with hierarchical pores and channels was prepared to realize efficient catalysis. This design utilizes light to excite electrons and holes and draws upon ultrasound to separate these carriers. Benefited from the synergism between light and ultrasound, more electrons and holes take part in chemical reaction and effective piezo-photocatalytic performance is realized. As the result, the piezo-photocatalytic performance of the PTO-PVDF sponge is 1.79 and 2.04 times that of its photocatalytic and piezocatalytic performance, respectively. Compared with the PTO-PVDF film, the performance is elevated by 2.67 times. In addition, the PTO-PVDF sponge displays high elasticity and low density, maintaining its shape after hundreds of compressing-relaxing cycles, making it potential for the applications such as low-intensity energy assisted photocatalysis. Through a facile preparation method, this design sheds light on the practical application of piezo-photocatalysis.