【Abstract】 The surface photovoltage spectra (SPS) of a series of samples Bi:PMo12Oy(x=2 ~ 9, y=43 ~ 64) were measured. It was found that with the increase of Bi/P molar ratio, SPS dribits regular evolutions characteristic of modulated surface band bendings. Another mperbont using the samples as catalysts in selective oxidation of propane showed that the Bi/P molar ratio influences the basic capacity of vacancies in the scheelite-type structure; and thus it influences the surface band bending. A simple model was presented to account for the effect of band bending on photovoltages due to bandgap and sub-bandgap illumination.更多还原