TiOub>2ub>/TiCub>0.7ub>Nub>0.3ub> coatings were prepared by ball milling followed by oxidation.
In situ co-doping of C and N with simultaneous TiOub>2ub> formation was observed.
Improved photocatalytic activity under UV/visible light was noticed.
Synergism in co-doping and heterojunction formation promoted carrier separation.