Fabrication of Doped Tin Oxide Electrode for Electrochemical Generation of Ozone

Ozone is increasing applied to water treatment 1 , odour removal, bacteria control 2 , and semiconductor treatment 3 .Electrochemical ozone production 4-6 (EOP) in aqueous phase provides a viable alternative to the conventional corona discharge process of generating ozone in the gas phase.Ozone can be electrochemically generated through water oxidation according to the reaction 3H 2 O Æ O 3 + 6 H + + 6 e -Eq=1.51V .(1) At the same time, the thermodynamically preferred oxygen evolution reaction (OER) occur at a lower potential according to the reaction 2H 2 O Æ O 2 + 4 H + + 4 e -Eq=1.23 V .(2) Recently, nickel and antimony doped tin oxide (NATO) was shown to be an effective material for electrochemical ozone generation 7-9 .In this study, we investigate ozone generation efficiency on doped SnO 2 electrodes fabricated by different methods.Metal chloride precursors including SnCl 4 •5H 2 O, SbCl 3 and NiCl 2 •6H 2 O were used for anode preparation by dip-coating pyrolysis method.Metal alkoxides composed of Sn(OC 3 H 7 ) 4 , Sb(OC 3 H 7 ) 3 , and Ni(OC 3 H 7 ) 2 were employed for sol-gel dip-coating study.It is found that anodes prepared by dip-coating pryorlysis method showed a higher current efficiency than those fabricated by sol-gel method.The highest current efficiencies of NATO anodes prepared by pyrolysis method and sol-gel method were 27.42% and 4.60%, respectively.The highest current efficiency was achieved at much lower potential for anodes prepared by pyrolysis method.This may be due to the higher conductivity of NATO electro-catalysts prepared by pyrolysis method.