Fig. 3From: Enhancement of TiO2 activity under visible light by N,S codoping for Pb(II) removal from waterFTIR spectra of a TiO2, b TiO2-N,S (1:1:0.5), c TiO2-N,S (1:1:1), and d TiO2-N,S (1:1:1.5)Back to article page