The presence of oxygen shows improvement in carbon photo-oxidation with nitric oxide.
Carbon is selectively converted into CO2 while NOx is reduced to N2.
The formation of nitrate on TiO2 is proved to be in a dynamic process.
Uniform size reduction of the carbon particles in the presence of NO, O2 and H2O was observed with HR SEM, in spite of the distance to TiO2 photocatalytic particles.