Fe-based Prussian blue cubes confined in graphene oxide nanosheets for the catalytic degradation of dyes in wastewater

Abstract

To remove the organic micropollutant from wastewater, an efficient and continuous technology was developed by the synergistic effect between membrane separation and Fenton oxidation reaction. The highly efficient heterostructured membrane was fabricated through a simple pressure-driven filtration of two-dimensional material graphene oxide (GO) nanosheets and three-dimensional cubic Prussian blue (PB) cubes, in which PB cubes were encased by GO nanosheets to form a sandwich construction. The composite membrane acts as a nano-micro reactor for the confined PB cubes to remove the micro contaminant during the filtration process. When the dyestuff wastewater passes through the membrane, the Fenton oxidation reaction was induced by the PB cubes embedded in the channels between the neighboring GO nanosheets. It is found that low-rate flow and high PB cubes loading were beneficial to degrade the dyes in water. In addition, the reversible conversion of Fe(III)/Fe(II) on cubic lattice sites endowed the membrane with a stable catalytic efficiency of 98 % and an almost unchanged flux of 27 L m−2 h−1 during the continuous filtration of methylene blue solution for 24 h under 1 bar. This work provides a novel strategy for the separation and degradation of the dyes in wastewater.