Porous (K0.5Na0.5)0.94Li0.06NbO3-polydimethylsiloxane piezoelectric composites harvesting mechanical energy for efficient decomposition of dye wastewater

•The KNN6L-PDMS porous composites have been successfully achieved with both the excellent piezoelectric properties and mechanical flexibility.•The piezo-catalytic activity exhibited a high efficiency and superior repeatability for degrading organic pollutants.•COMSOL simulations determined that piezo-catalysis was originated from the generated potential of piezoelectric composites.