Concurrent photocatalytic degradation and filtration with bi-plasmonic TiO2 for wastewater treatment

Abstract

A new photocatalytic filtration membrane was prepared by grafting of Ag–Au bi-plasmonic shell-on TiO2@Fe3O4 nanoparticles as a magnetically-separable heterogeneous photocatalyst to a poly acrylic acid-modified cellulose acetate membrane for decomposition and removal of methyl orange as a model pollutant from textile wastewater samples. Eight photocatalysts including five Au NPs-modified TiO2@Fe3O4 NPs and three Ag-Au bi-plasmonic NPs-decorated TiO2@Fe3O4 NPs with different shell thickness were synthesized and characterized by TEM, UV–vis, and SEM techniques and their photocatalytic activity was assessed using two radiation sources. After selection of optimum photocatalyst and modification of cellulose acetate membrane, the photodegradation of methyl orange was evaluated in a dead-end membrane reactor using the prepared membrane. The flux performance, antifouling property and pollutant removal efficiency of the membrane were evaluated using textile wastewater samples. It was demonstrated that the prepared membrane reactor is able to produce cleaner water with more stable flux performance and good antifouling property.