Sputter -coated N-enriched mixed metal oxides (TaO-NbO-N) composite: A resilient solar driven photocatalyst for water purification.

This study demonstrated the formation of N-enriched mixed metal oxides (TaO-NbO-N and TaO-NbO) thin film composites used as photocatalysts to degrade P-Rosaniline Hydrochloride (PRH-Dye) dye under solar radiation. By controlling the N gas flow rate during the sputtering process, the N concentration in the TaO-NbO-N composite is significantly included, and demonstrated by XPS and HRTEM analysis. With the help of XPS and HRTEM investigations, it was determined that the addition of N to TaO-NbO-N significantly enhances the active sites. The Ta-O-N bond (N 1 s and Ta 4p spectra) was verified by the XPS spectra. TaO-NbO was found to have a lattice interplanar distance (d-spacing) of 2.52, whereas TaO-NbO-N showed the 2.5 (620 planes). A sputter-coated TaO-NbOand TaO-NbO-N photocatalysts were prepared, and their photocatalytic activity was evaluated using PRH-Dye as a model pollutant under solar radiation by adding HO (0.01 mol). The photocatalytic activity of the TaO-NbO-N composite was compared with TiO (P-25) and TaO-NbO. TaO-NbO-N showed very high photocatalytic activity compared to Degussa P-25 TiO and TaO-NbO under solar radiation and confirmed the presence of N in TaO-NbO-N significantly increased the generation of ˙OH radicals (in pH 3, 7 and 9). With the use of LC/MS, the stable intermediates or metabolite created during the photooxidation of PRH-Dye were assessed. The results of this study will provide useful insights on how TaO-NbO-N influences the efficiency of water pollution remediation.