Results of FTIR analysis of SiO2/C, seen in Fig. 2b, are in agreement with XRD results, again showing only bands corresponding to silica (Scian and Volzone, 2001): two absorption bands at 1097 and 799 cm1, associated with the silica Si–O bond (Zhao et al., 2011), and two bands in 3045 and 1628 cm1, associated with the Si–OH bond (Liu et al., 2005).