Photochromic and hydrophilic self-cleaning nature of MoO3 thin films

MoO3 thin films were synthesized by thermal evaporation method with thicknesses of 300, 400, and 500 nm on FTO substrate. The reversible photochromic (examined under sunlight irradiation) and hydrophilic properties of thermally evaporated MoO3 thin films were studied. The thin films were characterized by XPS, XRD, and AFM. The surface of the prepared thin films turned to blue color from transparent white when the films were exposed to sunlight irradiation for 60 min, and also a decrease in the transmittance was observed. It was noted that the bleaching of the thin films occurred by placing the thin films in an atmosphere of oxygen at 300 degrees C and then placing it in the dark for 72 h. The corresponding variations in transmission spectra by the action of sunlight irradiation and bleaching were recorded by UV-Vis spectroscopy. Transmission spectra of the thin films confirmed that the prepared thin films have an excellent photochromic property with remarkable reversibility. The surface wettability property of the thin films was studied by using water contact angle measurements. MoO3 thin film with 300 nm thickness showed better photochromic and hydrophilic properties.