Photo-catalytic effect enhanced by the chemisorption of phenylethyl-mercaptan-assembled monolayers on Au-clusters/TiO2-anatase thin film

A simple process is employed to increase the efficiency of TiO2 photo-catalytic activity, for which the recombination probability of electron–hole pairs is relaxed. Au is selectively deposited on a high-transparency TiO2-anatase thin film on a glass substrate, and then phenylethyl mercaptan (PEM) is chemisorbed onto the selectively covered Au-clusters/TiO2-anatase thin film. The enhancement of the photo-catalytic activity on the PEM/Au-clusters/TiO2-anatase thin film is evaluated via the induced degradation of methylene blue. The results demonstrate that the Au coverage ratio on TiO2-anatase thin film and the photo-catalytic activity of the chemisorbed PEM/Au-clusters/TiO2-anatase are related. The photo-catalytic contribution of PEM/Au-clusters/TiO2-anatase differs from that of Au on a TiO2-anatase thin film. An optimized photo-catalytic system, a composite of PEM/3.8% Au-clusters/TiO2-anatase thin film, is proposed. The efficiency of the PEM/3.8% Au-clusters/TiO2-anatase thin film is 52.1% higher than that of the as-deposited TiO2-anatase thin film.