in neat (no solvent) Irradiation (UV/VIS); photochemical decompn. of SO2 in light of a H2-lamp (wave length below 200 nm), about 10°C, 0.5 Torr, mechanism discussed;;
in hydrogenchloride; sulfuric acid stirring hot soln. of TiO2 in 96percent H2SO4 containing (NH4)2SO4 and nickel sulfate in concd. HCl;; ppt. washed with aq. HCl and dried 4 h;;
