N, S co-doped and N-doped Degussa P-25 powders with visible light response prepared by mechanical mixing of thiourea and urea. Reactivity towards E. coli inactivation and phenol oxidation

摘要: Abstract Degussa P-25 powder was mixed mechanically with thiourea and urea then annealed during 1 h at 400 °C. Diffuse reflectance spectroscopy (DRS) revealed that treated powders absorb visible light (between 400 550 nm) by Kubelka–Munk relations it possible to estimate their band-gap energies, being 2.85 2.73 eV powders, respectively. X-ray photoelectron (XPS) showed in the case of P-25, hints interstitial N-doping anionic S-doping. On other hand, only presence N-doping. Atomic concentrations measured XPS highest content N species on TiO2 surfaces (2.7 at%) while presented low S (0.61 0.68 at%, respectively). Specific surface area (SSA) BET method, obtaining values 52 46 m2 g−1 for undoped 400 °C 1 h. N, co-doped N-doped SSA 42 40 m2 g−1, We suggest probably OH radical is not directly involved oxidative processes taking place when exposed light.