Fig. 4From: Enhancement of TiO2 activity under visible light by N,S codoping for Pb(II) removal from waterThe results of Pb(II) photo-oxidation under visible exposure over: (1) TiO2, (2) TiO2-N,S(1:1:0.5), (3) TiO2-N,S(1:1:1), and (4) TiO2-N,S(1:1:1.5)Back to article page