Preparation of the all-solid-state Z-scheme WO3/Ag/AgCl film on glass accelerating the photodegradation of pollutants under visible light

Tungsten oxide (WO 3 ) is a well-known photocatalyst, but its application is restricted due to its low conduction band and reduction power. In addition, WO 3 catalyst in powder forms has little application prospect because of difficulties in separation and regeneration. In this work, we prepared WO 3 /Ag/AgCl films on conventional glass that not only have much enhanced photocatalytic capability but also can be readily regenerated. The WO 3 film was prepared on glass substrate by calcination of spin-coated W precursor. Ag/AgCl particles were then deposited on WO 3 film by an impregnating–precipitation–photoreduction method. The photocatalytic efficiency of WO 3 /Ag/AgCl was evaluated by using methyl orange (MO) and Rhodamine B (RhB) as target pollutants. The highest photocatalytic performance was achieved with the 3-WO 3 /Ag/AgCl film, being 18 and 13 times higher than that of pure WO 3 film for degradation of MO and RhB, respectively. The degradation rate for both MO and RhB by 3-WO 3 /Ag/AgCl film catalyst decreased by less than 5% after five cycled tests. The photodegradation mechanism was discussed based on the electrochemical impedance spectroscopy Nyquist tests, photoelectrochemical analysis and reactive oxygen species scavenging experiments. A possible all-solid-state Z-scheme mechanism is proposed based on the photoelectron chemical tests and radical trapping experiments. This study provides a feasible technique to prepare a photocatalytic film with practicability and reproducibility.