“…Adsorption peaks of Si–O at 1200 and 468 cm –1 are stronger in the CO 2 4h sample compared to those in the CO 2 0h sample, which is consistent with its increased oxygen content. The adsorption peak at 808 cm –1 is assigned to Si–C bonding. , Small peaks at 1345 and 1618 cm –1 are attributed to the D and G bands of carbon in Si(CO) y , respectively, which indicates that some of the carbon may be in its elemental form. Otherwise, the IR result confirms the formation of Si–O, Si–C, and C–O bonds in the CO 2 -milled samples.…”