Unveiling intrinsic electrochemical mechanism of supporting electrolyte and interaction mechanism in electrochemical oxidation tetracycline with nano-PbO2

Abstract

Electrochemical oxidation (EO) for the removal of antibiotics is a promising technique because of green and sustainable electrical−to−chemical energy conversion. However, the interaction mechanism between different electrolytes molecule and organic pollution along with the generation pathway of reactive oxygen species remain unclear. Here, the β−PbO2 electrode was successfully prepared and employed as an effective tool for organic pollution removal. The EO process with β−PbO2 electrode and Na2SO4 electrolyte could completely remove tetracycline (TC) and achieve an impressive kinetic rate constant of 0.239 min−1. Quantum chemical calculations confirmed that hydrogen bonding was the primary binding force between TC and Na2SO4. Density functional theory calculations emphasized the key roles of radical and non−radical pathways in TC removal via the key reaction site (O atom in PbO2). Consequently, this study provided a novel insight into the intrinsic electrochemical behavior changes under various electrolyte, paving the way for novel electrochemical process in water treatment applications.