Boosted electrochemical reduction detoxification and oxidation of clofibric acid by polymerized ionic liquid functionalized cathode: Parameter optimization and degradation mechanisms

The application of electrocatalytic degradation technology in the treatment of pharmaceuticals and personal care products (PPCPs) has attracted widespread attention currently. Through structure and properties characterization of catalysts we found that more uniformly distributed metal particles and excellent thermal stability were obtained by modification with poly(1-vinyl-3-butylimidazole hexafluorophosphate) ([(PV)BIM]PF6) on graphene to anchor the metal CoNi nanoparticles (CoNi/PILs-rGO). For assessing its application potential, the CoNi/PILsrGO cathode in combination with Ti/RuO2/IrO2 anode to set up an experimental reaction system for the electrocatalytic degradation of clofibric acid (CA) simulated wastewater. Reactor settings for experimentation are optimized, and intermediates, alterations in toxicity during degradation, and active species are detected. The results of the single-factor experiment showed that the average removal rate of CA by the cathodic compartment was 97.18 % when the conditions were optimal. Two possible pathways of degradation are deduced from the CA intermediates, one is the C-Cl bond breaking in electrochemical reduction, and the other is that the C-O bond is directly broken by anodic reactive oxygen. Toxicity tests have shown that the anode produces some by-products that are more hazardous than the original chemical, while the cathode produces a dechlorination process that is ultimately more detoxifying.