Electrochemical Degradation of Tetracycline Hydrochloride in Aqueous Solution at β-PbO₂/α-PbO₂/Ni Electrode

The escalating contamination of aquatic ecosystems by recalcitrant antibiotics, specifically tetracycline hydrochloride (TC), necessitates the development of robust remediation technologies. Electrochemical oxidation presents a viable solution for wastewater treatment through the continuous generation of highly reactive hydroxyl radicals (•OH). While lead dioxide (PbO₂) electrodes are widely regarded for their substantial oxygen evolution overpotential, traditional planar configurations frequently suffer from physical delamination driven by internal mechanical stress, thereby severely limiting their operational lifespan. To address this critical durability challenge, we engineered a novel β-PbO₂/α-PbO₂/Ni composite electrode. Ni mesh was utilized as the substrate to inherently dissipate internal mechanical stresses. The fabrication process involved the sequential electrodeposition of α-PbO₂ inner layer to ensure robust interfacial adhesion, followed by β-PbO₂ outer layer to maximize electrocatalytic activity. The electrochemical degradation of TC was subsequently conducted to systematically evaluate both the remediation performance and the structural durability of the fabricated anode. The newly developed electrode exhibited superior structural integrity and catalytic efficiency compared to conventional planar electrodes. Ni mesh successfully mitigated internal stress accumulation, effectively preventing the delamination of the PbO₂ active layers during continuous electrolysis. During the degradation assays, the β-PbO₂/α-PbO₂/Ni anode achieved a remarkable TC removal efficiency of over 90% within 120 minutes. Accelerated life testing further confirmed a significant extension in the electrode's service lifespan, maintaining consistent •OH generation without mechanical failure. Ultimately, this robust composite electrode system demonstrates exceptional longevity combined with high catalytic activity, offering a highly practical approach for the sustained electrochemical treatment of antibiotic-contaminated wastewater.