A TiO2 modified with PtⅣ chloride was investigated by diffuse reflectance UV-Vis spectra（DRS）,X-ray photoelectron spectroscopy（XPS）, surface photovoltage spectroscopy（SPS） and electric field-induced surface photovoltage spectroscopy（EFISPS）.XPS showed that a Ti-O-PtⅣClx surface complex between PtⅣ chloride and TiO2 appears to be responsible for visible light absorption.An electron transfer from the surface-complexed PtⅣClx to the conduction band of TiO2 upon absorbing visible light was confirmed by SPS and EFISPS.
