Efficient piezocatalytic removal of BPA and Cr(VI) with SnS2/CNFs membrane by harvesting vibration energy

Piezocatalysis that converts mechanical energy into chemical energy plays an important role in environmental purification and energy regeneration. In this work, a piezoelectric membrane of carbon nanofibers coated by few-layers SnS 2 nanosheets , a typical layered transition metal dichalcogenides (TMDs), for the first-reported piezocatalysis of hexavalent chromium (Cr (VI)) and bisphenol A (BPA). A boosted removal efficiency of Cr (VI) and BPA under ultrasonication are 3 and 4 times higher than that under illumination, respectively, which is attributed to the built-in electric field and band bending derived from the piezoelectricity of SnS 2 as well as the outstanding electronic liquidity of CNFs substrate. It was also found that the most oxidizing ·OH can be generated in SnS 2 /CNFs for piezocatalytic oxidative degradation of BPA compared to the absence of ·OH under illumination. Finally, the possible piezocatalytic mechanism of SnS 2 /CNFs is proposed. So it provides a new view on piezocatalysis of TMDs for environmental remediation by collecting mechanical energy.