Photodeposition Ag/TiO2 with fine silver clusters exhibited better activity for photocatalytic reduction of nitrate anions than Ag/TiO2 catalyst prepared by a traditional method.
Under the modification of 0.04 mol/l formic acid as a hole scavenger, the as-prepared 1wt% Ag/TiO2(A) catalyst was found to exhibit as much as 98% nitrate conversion for
443 agNO3−/l nitrate solution and 100% selectivity for nitrogen after 30 min of UV illumination.
The average activity was calculated to be 24 mmol SO3− g−1Ag min−1, which is much higher than the average activity for most noble-metal based nitrate hydrogenation systems.
The results demonstrate that the photocatalytic reduction of nitrate in drinking water maybe a promising denitrification method, especially with the development of applications involving sunlight.