Standardised nanostructured Ta/N-TiO2 For environmental contaminants: an efficient visible light induced photochemical quencher for dyes.

Visible light photocatalysis by semiconductor nanomaterials is one of the promising methods due to its sustainable nature and cost effectiveness. Co-doping in TiO2 by metal as well as non-metal ion is an effective way to make it an efficient visible light photocatalyst. In this work, highly competent nanostructured Ta/N-TiO2 has been standardised by following sequential trials on series of tantalum and nitrogen co-doped TiO2 and characterised by PXRD, UV-Vis-DRS, SEM-EDAX, TEM and XPS. Diffuse reflectance-UV-Vis spectroscopy (UV-Vis-DRS) of the particles revealed that optical band gaps were decreasing only up to 20 mol% of the Ta content. It was observed, the doping percentage of Ta was found to significantly control the extent of N incorporation into the particles. Sunlight stimulated photocatalytic dye degradation experiments were performed over aqueous methylene blue (MB) and the Ta/N co-doped TiO2 particles containing 20 mol% of Ta displayed the paramount photocatalytic activity. Photocatalytic disinfection also performed over E. coli, S. aureus and Bacillus employing 20 mol% of Ta/N-TiO2. Significant amount of inhibition found in E. coli and S. aureus and possible killing mechanism are discussed in 'Result and discussion' section. The co-doped TiO2 has dual advantage to act both as a visible light active photocatalyst and antibacterial agent. [ABSTRACT FROM AUTHOR]