Fabrication of PbO2/SnO2 composite anode for electrochemical degradation of 3-chlorophenol in aqueous solution

In present work, SnO2 nanoparticles were synthesized using simple hydrothermal process, and then a novel PbO2/SnO2 electrode was successfully fabricated using obtained SnO2 nanoparticles for electrochemical oxidation of 3-chlorophenol (3-CP). The microstructure, element distribution, crystal structure and chemical composition of samples were characterized by the analytical techniques including SEM, EDS, XRD and XPS. The electrochemical performances of electrodes were evaluated using LSV and CV measurements. The center dot OH radicals generation capacity of electrodes was determined using terephthalic acid as trapping agent. Moreover, the PbO2/SnO2 electrodes were applied in the electrochemical degradation of 3-CP in aqueous solution. The results show that the doping of SnO2 nanoparticles reduced the grain size of PbO2 crystal and improved the content of Oads on the surface of electrode. In contrast with the pure PbO2 electrode, the PbO2/SnO2-1.0 electrode (the concentration of SnO2 in electroplating solution was 1.0 g/L) exhibited higher oxygen evolution potential, stronger direct oxidation capacity and center dot OH radicals generation capacity, and superior electrochemical activity for degradation of 3-CP. The intermediates formed in electrochemical degradation of 3-CP were revealed by HPLC and a plausible degradation pathway was proposed. Furthermore, PbO2/SnO2-1.0 electrode also showed a high reusability for 3-CP degradation.