Is Black Titania a Promising Photocatalyst?

Five different (commercial and self-synthesized) titania samples were mixed with NaBH4 then heated to obtain black samples. The change in synthesis conditions resulted the preparation of nine photocatalysts, most which color. photocatalysts characterized by various methods, including X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), photoelectron (XPS), scanning transmission electron microscopy (STEM), photoacoustic reverse-double beam (PAS/RDB-PAS). photocatalytic activity was tested for oxidative decomposition acetic acid, methanol dehydrogenation, phenol degradation bacteria inactivation (Escherichia coli) under conditions, i.e., irradiation UV, vis, NIR, dark. It found that properties obtained depended on features original materials. A shift XRD peaks observed only case commercial samples, indicating self-doping, whereas faceted anatase (self-synthesized) showed high resistance towards bulk modification. Independent type degree modification, all modified exhibited much worse UV than both aerobic anaerobic conditions. is proposed strong reduction during samples’ partial destruction surface, as evidenced microscopic observation crystallographic data (an increase amorphous content), thus formation deep traps (bulk defects oxygen vacancies) increasing charge carriers’ recombination. Under vis irradiation, a slight performance (phenol degradation) four while two also NIR. In inactivation, some higher NIR respective pristine titania, could be useful disinfection, cancer treatment other purposes. However, considering overall this study, it difficult recommend them broad environmental applications.