Assembly of MOF derived composite catalyst on the PVDF membrane matrix for high-efficient phenol removal

Abstract

Integrating the heterogeneous catalysts with the membrane matrix is a promising approach for wastewater decontamination. In this study, a ZIF-67 derived cobalt‑manganese spinel catalyst MnCo2O4.5@Carbon (MCOC) was prepared using a one-pot pyrolysis process and was then blended with a polyvinylidene fluoride (PVDF) membrane through the phase inversion method. The introduction of the MCOC catalyst not only improved the permeance of the membrane but also constructed active reaction sites within the membrane matrix. As a result, the PVDF/MCOC membranes exhibited both satisfactory degradation capabilities by activating peroxymonosulfate and favorable permeation performance. Remarkably, about 99 % of phenol (20 mg/L) can be removed within 30 min, with a water flux of 649.0 L/m2∙h. Besides, the PVDF/MCOC catalytic membrane possessed favorable anti-fouling properties and stability. The flux recovery rate of the PVDF/MCOC membrane reached 85 % after three fouling/washing cycles, while the phenol removal efficiency remained consistent at 95 % after 5 consecutive cycles. Radical quenching tests and electron paramagnetic resonance analysis further indicated that sulfate radicals and singlet oxygen were the primary reactive oxygen species in the phenol degradation processes. Consequently, this work highlights an effective method to fabricate a catalytic membrane with high permeance and catalytic efficiency, potentially expanding the application of heterogeneous catalysts in wastewater decontamination.