Identification of the Mechanism of Electrocatalytic Ozone Generation on Ni/Sb-SnO2

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• 作者：P. A. ChristensenP. S. Attidekou ; R. G. Egdell ; S. Maneelok ; D. A. C. Manning ; R. Palgrave
• 刊名：Journal of Physical Chemistry C
• 出版年：2017
• 出版时间：January 19, 2017
• 年：2017
• 卷：121
• 期：2
• 页码：1188-1199
• 全文大小：701K
• ISSN：1932-7455

文摘

This paper reports a systematic study of the codoping of SnO₂ with Sb and Ni to identify the mechanism responsible for the electrocatalytic generation of ozone on Ni/Sb-SnO₂. On the basis of interpretation of a combination of X-ray diffraction, BET surface area measurements (N₂), and thermal analysis, the formation of ozone appears to take place on particle surfaces of composite Sb-SnO₂ grains and is controlled by diffusion of OH along internal crystallite surfaces within the grain. Sb-doped SnO₂ is inactive with respect to ozone evolution in the absence of Ni, demonstrating a synergic interaction between nickel and antimony. From X-ray photoelectron spectroscopy (XPS) investigations, Sb(V) ions substitute for Sn(IV) in the lattice with a preference for centrosymmetric coordination sites, while the Sb(III) ions occur at grain surfaces or boundaries. Ni was not detected by XPS, being located in the subsurface region at concentrations below the detection limit of the instrument. In addition to identification of a possible mechanism for ozone formation, the study resulted in the production of active nanopowders which will allow the fabrication of high-surface-area anodes with the potential to exceed the space-time yields of β-PbO₂ anodes, permitting the application the Ni/Sb-SnO₂ anodes in the treatment of real waters.