Electrocatalytic composite membrane with deep-permeation nano structure fabricated by flowing synthesis for enhanced catalysis

Abstract

An electrocatalytic composite membrane with deep-permeation nano structure (DPNS) has been fabricated by flowing synthesis. The nano electrocatalyst MnO2 is in situ successfully assembled in membrane pores and uniformly immobilized in membrane pores along the direction of membrane thickness. The size of MnO2 nanoparticles immobilized in membrane pores is in the range of 33–35 nm, which is one-tenth of that immobilized on the membrane surface. The increased current density and the lower charge transfer resistance of the electrocatalytic composite membrane implied that a fast electron transfer can be achieved. As a concept-of-proof, the removal of phenol was applied to test the catalytic performance of the electrocatalytic composite membrane under the flow-through reaction mode, and the removal rate of phenol of being over 97% can be achieved under the condition of membrane flux of being 13.5 L m−2 h−1. The apparent reaction rate constant could be increased by 2–3 orders of magnitude, owing to the enhanced contact by uniform distribution of membrane pores, as well as the confined space effect of membrane pores and the flow-through synergism enhancing mass transfer. The species of free radical can be determined as ·OH via ESR measurements for phenol oxidation. This electrocatalytic composite membrane (ECCM) with DPNS has good reusability and can provide a promising prospect for industrial application.