B4C/Ce co-modified Ti/PbO2 dimensionally stable anode: Facile one-step electrodeposition preparation and highly efficient electrocatalytic degradation of tetracycline.

The application of PbO2 for electrochemical oxidation technology is limited by its low electrocatalytic activity and short service life. Herein, based on the facile one-step electrodeposition, we prepared a boron carbide (B4C) and cerium (Ce) co-modified Ti/PbO2 (Ti/PbO2-B4C-Ce) electrode to overcome these shortcomings. Compared with Ti/PbO2 electrode, the denser surface is displayed by Ti/PbO2-B4C-Ce electrode. Meanwhile, electrochemical characterization indicates that the introduction of B4C and Ce significantly enhance the electrochemical performance of PbO2 electrode. In degradation experiments, under optimized conditions (current density 20 mA cm-2, pH 9, 0.15 M Na2SO4 and 30 °C), the fully degradation of tetracycline (TC) can be completed within 30 min. Furthermore, the trapping experiment demonstrates that ∙OH and SO4·- radicals have a synergistic effect in the degradation process of TC. Based on results of liquid chromatography-mass spectrometer, the generated ·OH preferentially attacks amides, phenols and conjugated double bond groups in TC. Importantly, Ti/PbO2-B4C-Ce electrode maintains a constant degradation efficiency even after 10 recycling tests, and its service life is 2.4 times of traditional Ti/PbO2 electrode. Hence, Ti/PbO2-B4C-Ce electrode is a promising electrode for degradation of organic wastewater containing amides, phenols, and conjugated double bond groups.

One-step electrodeposition preparation of boron nitride and samarium co-modified Ti/PbO2 anode with ultra-long lifetime: highly efficient degradation of lincomycin wastewater.

Lincomycin (LC) is an extensively applied broad-spectrum antibiotic, and its considerable residues in wastewater have caused a series of environmental problems, which makes degradation of LC wastewater extremely urgent. In this work, we have constructed a novel boron nitride (BN) and samarium (Sm) co-modified Ti/PbO2 as anode for high-performance degradation of LC wastewater. Compared with Ti/PbO2, Ti/PbO2-Sm, and Ti/PbO2-BN electrodes, Ti/PbO2-BN-Sm electrode with smaller pyramidal particles possesses higher oxygen evolution potential (2.32 V), excellent accelerated service life (103 h), and outstanding electrocatalytic activity. The single-factor experiments demonstrate that under optimized conditions (current density of 20 mA.cm-2, 6.0 g L-1 Na2SO4, pH 9, and temperature of 30°C), removal rate and COD degradation rate of LC at 3 h have reached 92.85% and 89.11%, respectively. At the same time, degradation of LC is in accordance with the primary kinetic model. Based on the analysis of high-performance liquid chromatography-mass spectrometry (HPLC-MS), four possible degradation pathways are hypothesized. Therefore, efficient electrochemical degradation of LC by using an extremely long-life Ti/PbO2 electrode with high catalytic activity may be a promising method.