Non-radical dominated catalytic degradation of chlorophenol by a structure-tailored catalyst of high nitrogen doping carbon matrix with nano-CuO

Abstract

Non-radical oxidation process is very important in advanced oxidation for efficient degradation of the organics with electron-donating groups such as chlorophenols. In this work, a structure-tailored catalyst of high nitrogen doping carbon matrix with nano-CuO (CuO-NC) for efficient and dominant non-radical catalysis was successfully constructed and synthesized. As a persulfate (PS) activation catalyst, CuO-NC exhibits high catalytic activity in 4-chlorophenol(4-CP) degradation with removal efficiency of 100% within 30 min, strong resistance to coexisting substances (humic acid, Cl-, NO3-, HCO3-), wide suitable solution pH range (3.0–11.0). Electron paramagnetic resonance (EPR) analysis, quenching tests and electrochemical measurements verified the dominant non-radical catalysis via 1O2 generation and mediated electron transfer in the CuO-NC/PS/4-CP system. The possible 4-CP degradation pathway was also proposed. It is unveiled that the tailored electronic property and active sits (carbon structure defect and oxygen vacancies) are the reasons for the highly efficient non-radical catalysis on CuO-NC. In addition, the highly efficient non-radical system of CuO-NC possesses good reusability for PS activation and fine applicability in the degradation of organic with electron-donating groups. This study provides an effective strategy to rationally design non-radical catalysts for the efficient oxidative degradation of electron rich organic pollutants and deepens the understanding of non-radical catalysis for organic pollutants treatment.