Removal of organic contaminants by starch-derived porous carbon via peroxymonosulfate activation: The role of N doping and Fe/Mn loading

Abstract

In this work, Fe/Mn-loaded nitrogen-doped porous carbonaceous materials were synthesized by a one-step pyrolysis process for organic contaminants removal. The effects of the component ratios of starch, urea, sodium bicarbonate, iron and manganese salts and pyrolysis temperatures on the removal performance of bisphenol A (BPA) were discussed. FeMn@CN-800, which pyrolyzed at 800 °C with a mass ratio of starch∶urea∶Fe∶Mn = 100∶100∶0.34∶0.66 showed 95.4% BPA removal and 73.5% mineralization within 60 min. Large specific surface (663 m2 g−1), rich hierarchical pore structures and N-doping facilitated the adsorption of BPA and peroxymonosulfate (PMS). Fe and Mn are located in the carbon layer in the form of iron carbide and manganese oxide, and act as electron donors to activate the PMS. Chemical quenching tests and electron paramagnetic resonance (EPR) confirmed that hydroxyl radicals (•OH), sulfate radicals (SO4•‐), superoxide anion radical (O2•‐), and singlet oxygen (1O2) are the ROS in this system. Electrochemical tests showed the formation of catalyst-PMS complexes and catalyst facilitated the direct electron transfer from BPA to PMS. The effect of reaction parameters, cyclic experiments, possible BPA degradation pathways were investigated. This work provides the first systematic evaluation of starch-derived materials as high-performance catalysts for PMS-based advanced oxidation processes.