Comment on “Photoelectrochemical study of hydrogen in zirconium oxide”

Abstract Photoelectrochemical study of H + implanted Zirconium oxide was argued by Okui et al. [M. Okui, T. Nishizaki, M. Uno, K. Kurosaki, S. Yamanaka, K. Takeda, H. Anada, J. Alloys Compd., 330–332 (2002) 645–648]. Their study was to investigate the hydrogen in zirconium oxide film, while they drawn conclusions without considering the distribution of H + , so the discussion of results may be insufficient. Among results of photoelectrochemical properties of zirconium oxide film, photocurrent density dependence of applied potential may be inconsistent with the conclusion that the zirconium oxide film was n-type semiconductor.