Synergistic and electrocatalytic degradation of antibiotics by silver/protonated polyaniline-titanium-based composite electrodes in a common chamber reactor: Regulatory factors, degradation mechanism, toxicity assessment

The protonated polyaniline prepared by protonated electropolymerization exhibited a higher density of states at the Fermi energy level. Then, by depositing silver on the electrode surface, high electrocatalytic activity and good stability of silver/protonated polyaniline-titanium (Ag/H-PANI-Ti) electrodes were produced. The degradation efficiency of the Ag/H-PANI-Ti electrode for doxycycline hydrochloride (DOX) reached 83.33 % in 120 min under optimal parameters and in accordance with the pseudo primary reaction kinetics. The energy consumption was only 15.84 kWh/kg. The mechanism of DOX degradation through cathodic and anodic co-catalysis was put forth, and the degradation pathway was deduced. It should be highlighted that toxicology tests and toxicological evaluation based on ecological conformational relationships (ECOSAR) revealed that the biological toxicity of DOX was greatly decreased following degradation by the Ag/H-PANI-Ti electrode. Finally, the mechanism of enhanced Ag/H-PANI-Ti performance was illustrated by DFT first-nature principle calculations. The results showed that this study provides a viable option for the electrocatalytic degradation of antibiotics.