Simple development of Kelvin Probe using a pA meter and its application to study the photocatalytic activities of Ag/TiO2 and Ag2O/TiO2 coated polyester fabrics

Abstract The Ag/TiO2 and Ag2O/TiO2 films were deposited by magnetron sputtering on the polyester fabrics. The Kelvin probe system was simply developed and used to investigate the photoelectric properties of Ag/TiO2 and Ag2O/TiO2 junctions. The measured work functions of the deposited Ag, Ag2O and TiO2 are 4.65 e V , 5.53 e V and 5.03 e V , respectively. Ag2O/TiO2 junction has a 0.12 e V larger E F difference than Ag/TiO2 junction, indicating that Ag2O/TiO2 junction has a higher ability of charge separation than Ag/TiO2 junction. The photocatalytic activities of samples towards RB solution under 365 nm UV light were investigated. The results show that the Ag/TiO2 and Ag2O/TiO2 coated polyester fabrics have a far better photocatalytic performance than TiO2 coated polyester fabrics. And the photocatalytic activity of Ag2O/TiO2 coated sample is prominently higher than that of Ag/TiO2 coated sample, which is attributed to the larger E F difference and the wider space charge region of Ag2O/TiO2 junction compared with that of Ag/TiO2 junction.