Mn-Cu bimetallic electro-spun catalytic membrane coupled Fenton-like scheme for sulfamethoxazole destruction under ambient pH

Abstract

Heterogeneous catalyst reuse and the effectiveness of hydrogen peroxide (H2O2)-based advanced oxidation processes under near-neutral conditions remain an obstacle in wastewater remediation. Herein, we put forward a versatile catalytic membrane with Cu-doped MnO active layer anchoring on the polydopamine-modified electrospinning polyvinylidene fluoride (PDA@PVDF) base. The Cu-MnO@PDA@PVDF membrane was conferred admirable sulfamethoxazole (SMX) reduction (over 90% within 90 min) and clogging alleviation (relative flux recovery to 0.98) capabilities via in situ H2O2 activation at pH 8, which was slightly affected by actual water background. Electron paramagnetic resonance (EPR) and trapping tests unveiled the joint contribution of •OH, O2•− and 1O2, with •OH exerting the supreme role in SMX oxidation. The inherent characteristics of dual Mn-Cu centers on the membrane surface for facilitation of electron transfer, H2O2 adsorption and barrierless dissociation to •OH were further elucidated by electrochemical measurements and density functional theory (DFT) computation. Comprehensively, this study proposes a facile procedure and insights into engineering catalytic membrane coupled H2O2 strategy for refractory organic treatment at ambient conditions.