Nitrogen-modified nano-titania: True phase composition, microstructure and visible-light induced photocatalytic NOx abatement

摘要: Abstract Titanium dioxide (TiO2) is a popular photocatalyst used for many environmental and anti-pollution applications, but it normally operates under UV light, exploiting ∼5% of the solar spectrum. Nitrification titania to form N-doped TiO2 has been explored as way increase its photocatalytic activity visible anionic doping promising method enable harvest visible-light by changing photo-absorption properties. In this paper, we explore insertion nitrogen into lattice using our green sol–gel nanosynthesis method, create 10 nm NPs. Two parallel routes were studied produce nitrogen-modified nanoparticles (NPs), HNO3+NH3 (acid-precipitated base-peptised) NH4OH (totally base catalysed) sources. These NPs thermally treated between 450 800 °C. Their true phase composition (crystalline amorphous phases), well their micro-/nanostructure domain shape, size distribution, edge screw dislocation density) was fully characterised through advanced X-ray methods (Rietveld-reference intensity ratio, RIR, whole powder pattern modelling, WPPM). As pollutants, oxides (NOx) are particular concern human health, so assessed monitoring NOx abatement, both white-light (indoor artificial lighting), simulating outdoor indoor environments, respectively. Results showed that onset anatase-to-rutile transformation (ART) occurred at temperatures above 450 °C, heated 450 °C possessed excellent (PCA) with PCA double than standard P25 However, higher thermal treatment found be detrimental activity, due effects four simultaneous occurrences: (i) loss OH groups water adsorbed on surface; (ii) growth crystalline sizes decrease in specific surface area; (iii) progress ART; (iv) increasing instability lattice.