Self-cleaning MOF integrated membrane embedded with piezocatalytic Bi2WO6 nanocrystals for synergistic wastewater purification and dyes removal

Abstract

The widespread application of high-performance separation membranes in sewage purification is limited by their permeability and membrane fouling. Herein, we report a method for growing CAU-17 MOF on the flexible polymer substrate and embedding piezoelectric Bi2WO6 (BWO) nanocrystals based on Bi ion sites. The integrated membrane inherits the hydrophilicity and adsorption characteristics of MOF, showing a high flux and separation coefficient of 90.3% for rhodamine B (RhB) solution. In addition, this strategy optimizes the piezoelectric field of CAU-17 into the entire surface through surface modification of BWO nanocrystals. The piezocatalytic degradation rate constant of RhB reaches 0.040 min1. The flexibility and abundant mesoporous of polyvinylidene fluoride (PVDF) substrate provide the piezoelectric response to weak forces and more reactive active sites, enabling the integrated membrane to achieve dye degradation under low-frequency water flow. The BWO@CAU-17 evolved from MOF matrix enables self-cleaning of membranes. The synergistic function of multiple effects drives the rapid separation and complete degradation of pollutants, which greatly promotes the practical application of integrated membranes.