Integration of Microfiltration and Visible-Light-Driven Photocatalysis on a ZnWO₄ Nanoparticle/Nickel–Aluminum-Layered Double Hydroxide Membrane for Enhanced Water Purification

Abstract

Facing the increasing organic wastewater pollutants in the world, it is curious to discover novel materials for efficient wastewater separation and organic pollutants degradation. Hence, in order to solve the above problems, zinc tungstate nanoparticle/nickel–aluminum-layered double hydroxides/polyvinylidene fluoride composite photocatalytic membranes (ZnWO4/NiAl-LDH/PVDF) were constructed via vacuum filtration technology. In the following, multiple techniques were selected to characterize its physical and chemical structures. Results showed that the photocatalytic degradation performance of methylene blue was 93.97% with ZnWO4/NiAl-LDH composites and the corresponding rate constants were nearly 9.70, 2.42, and 2.06 times higher than commercial P25, NiAl-LDH, and ZnWO4 nanoparticles, respectively. After five cycles, the photocatalytic degradation rate still reached 85%. In addition, the rejection rate and water flux of ZnWO4/NiAl-LDH/PVDF membranes were 76.78% and 179.197 L·m–2·h–1 at 0.1 bar. Hence, the thoughts about ZnWO4/NiAl-LDH/PVDF membrane design can open a new insight to develop the new related photocatalysts and membrane separation techniques.