The 0.5 wt.% Fe–TiO2 catalyst was found to be more efficient than 1 wt.% Co or 1 wt.% Ni doped TiO2. Catalyst loading and initial pH of NB solution are important variables of the
process efficiency. The optimum concentration of catalyst is 250 mg/L. Degradation of NB by UV–VIS/Fe–TiO2 system is more favourable in neutral pH.