The values of the band gap are
shown in Fig. 10. The 1 ¼ TiO2 film shows the band gap 3 eV, the
2 ¼ TiO2/1.25 ml GO composite film shows 2.77 eV, the 3 ¼ TiO2/
2.5 ml GO composite film shows 2.74 eV, the 4 ¼ TiO2/3.75 ml GO
composite film shows 2.78 eV, and 5 ¼ TiO2/5 ml GO composite film
shows 2.71 eV.