Photocatalytic activity of BiOCl thin films deposited by thermal evaporation

Thin films of BiOCl were prepared by a sequential evaporation process in a Thermal Evaporation System (TES) starting from BiOCl powders previously synthesized by co-precipitation. The films with 300 nm of thickness were deposited with a rate of 0.12 Ås−1 to get a controlled evaporation of the material. BiOCl thin films deposited over microscope glass slides were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (HRTEM). The analysis by XRD confirmed the formation of BiOCl, showing a high degree of preferential crystalline orientation in {001} planes. In the same way, SEM analysis showed that the deposition of the oxyhalide took place by the formation of particles with shape of plates and small flowers. The photocatalytic activity of BiOCl thin films was evaluated in the degradation reaction of rhodamine B (RhB) in aqueous solution, and in the photocatalytic oxidation reaction of nitric oxide (NO) in gaseous phase. In both cases was confirmed the activity of the surface of the BiOCl films when it was activated by sun-like irradiation.