Photocatalytic Reduction of Nitrate over Fe-modified TiO2

This research work investigated the photocatalytic nitrate reduction under the system using Fe-TiO2 thin film catalyst with formic acid as the hole scavenger and irradiation with black-light fluorescence lamps. The Fe-TiO2 thin films with 0.1% weight by volume (w/v) of Fe as dopant were coated onto the 304 stainless steel surface by the sol-gel method. The system showed the overall nitrate removal efficiency of 70.44% with the net photocatalytic nitrate reduction efficiency of 65.97%. The stoichiometric ratio of net formate to nitrate was 2.86 to 1.0, which is close to the theoretical ratio of 2.5 to 1.0 for nitrate reduction to nitrogen gas. The presence of nitrite in the system together with the aforementioned formate to nitrate ratio indicated that the main mechanism of nitrate removal was nitrate reduction to nitrogen gas.