Figure 2 shows the absorption spectra of B-TiO2 doped with boric acid triethyl ester prepared by grinding of ST-01 with a
dopant. The best photoabsorption in the visible region can be attributed to the sample showing the higher photoactivity in the
reaction of phenol degradation - BE-G(2). We did not observe a red shift for boron-doped photocatalysts but some samples show
lack of sharp absorption edge as observed for pure TiO2.