Facile preparation of a silver nanoparticles-containing membrane with an enhanced catalysis and separation

Abstract

A composite membrane was facilely fabricated by the simultaneous in situ reducing silver ions and anchoring of the formed silver nanoparticles (NPs) inside a poly (dopamine) (PDA)-modified poly (vinlidene fluoride) (PVDF) membrane which was prepared by the PVDF powders modified via dopamine. The composite membrane showed a typical unsymmetrical structure with membrane surface and pore having Ag NPs. The PDA of the membrane effectively prevented the Ag NPs’ agglomeration and leaching, beneficial to the Ag NPs’ catalysis and stability. When a cross-flow model was applied to circulate p-nitrophenol through the composite membrane, a rapid catalytic reduction could be obtained. Ag NPs of the membrane surface have the main contribution to the catalysis compared with the ones of membrane pores. However, Ag NPs of membrane pores could efficiently catalyze the reduction of the reactants flowing through the membrane pores more thoroughly. By the synergy of Ag NPs on membrane surface and in membrane pores, highly purified products could be directly separated from the system during reaction process. In the whole process, additional steps for separating Ag NPs and products were omitted, significantly decreasing the operating cost. In addition, the Ag NPs of the composite membrane obtained high reactive activity. All the advantages make the composite membrane have attractive prospects for catalytic reaction and separation.