Chemistry of NOx on TiO2 Surfaces Studied by Ambient Pressure XPS: Products, Effect of UV Irradiation, Water, and Coadsorbed K(.).

Self-cleaning surfaces containing TiO2 nanoparticles have been postulated to efficiently remove NOx from the atmosphere. However, UV irradiation of NOx adsorbed on TiO2 also was shown to form harmful gas-phase byproducts such as HONO and N2O that may limit their depolluting potential. Ambient pressure XPS was used to study surface and gas-phase species formed during adsorption of NO2 on TiO2 and subsequent UV irradiation at λ = 365 nm.

Enhanced CO photocatalytic oxidation in the presence of humidity by tuning composition of Pd-Pt bimetallic nanoparticles supported on TiO2.

Here we put forward for the first time that the negative effect of humidity on CO photooxidation at room temperature can be overcome by adjusting the composition of Pd-Pt bimetallic particles supported on TiO(2). Consequently, optimized Pd(x)Pt(1-x)/TiO(2) materials can be considered as common and efficient photocatalysts for simultaneous elimination of CO and VOCs in the presence of humidity, i.e.