N-doped, S-doped TiO2 nanocatalysts: synthesis, characterization and photocatalytic activity in the presence of sunlight

N doped and S doped nano TiO2 catalysts were synthesized by a sol-gel process followed by hydrothermal treatment at low temperature and tested for catalytic activity by natural sunlight photocatalytic degradation of a toxic chemical warfare agent. It is observed that sulfate groups were anchored on the surface of titania upon doping, and also create active surface oxygen vacancies, both of which are responsible for sunlight absorption and the promotion of electrons to the conduction band. The formation of a superoxide radical (O-2(center dot-)) and hydroxyl radicals may be mainly responsible for the photodegradation of sulfur mustard under sunlight.