Facile sealing treatment with stannous citrate complex to enhance performance of electrodeposited Ti/SnO₂-Sb electrode

Ti/SnO₂-Sb is a promising anode for electrochemical advanced oxidation process with advantages of low cost and no secondary pollution, while suffers from low work economy due to the short service life. In this study, a facile strategy was proposed to fabricate Ti/SnO₂-Sb electrode with high oxidation ability and long service life based on novelly sealing electrodeposited Sn-Sb coating with stannous citrate complex. The treated Ti/SnO₂-Sb electrode exhibited an accelerated service life of 41.5 h (100 mA cm^-2; 0.5 M H₂SO₄) and a degradation rate constant for methylene blue dye of 1.02 h^-1 which were respectively 11.9 and 2.5 times as that of the untreated electrode. It was found out that the complex could well repair the coating defects inside or outside and form a covering film to tighten the coating, and was then mineralized during the following calcination process to achieve a uniform, rough and highly active SnO₂-Sb catalytic layer. The distinctive structure was confirmed by XRD, SEM, XPS and FT-IR. The sealing treatment could be achieved by in situ electrodepositing Sn-Sb coating from or ex situ dipping Sn-Sb coating in solution containing stannous citrate complex followed by drying in air. This study provided a novel, facile and effective strategy to enhance performance of Ti/SnO₂-Sb electrode that could be easily achieved in both laboratory and industrial scales and combined with other strategies.