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 SnS2 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 SnS2 as well as the outstanding electronic liquidity of CNFs substrate. It was also found that the most oxidizing ·OH can be generated in SnS2/CNFs for piezocatalytic oxidative degradation of BPA compared to the absence of ·OH under illumination. Finally, the possible piezocatalytic mechanism of SnS2/CNFs is proposed. So it provides a new view on piezocatalysis of TMDs for environmental remediation by collecting mechanical energy.