Surface functionalization of graphene oxide using amino silane magnetic nanocomposite for Chromium (VI) removal and bacterial treatment

Abstract

Abstract Amino silane magnetic nanocomposite decorated on graphene oxide (GO-Fe 3 O 4 -APTES) was successfully prepared by organic transformation reaction followed by co-precipitation method. The nanocomposite was characterised by using FT-IR, XRD, FE-SEM, TEM, EDS mapping, VSM, Raman spectroscopy, BET surface area analyzer, Zeta potential and UV-visible spectrophotometer. From TEM results we observed that 8 nm sized particles successfully modified on GO surface. The surface area of GO-Fe 3 O 4 -APTES was 57.9 m 2 g −1 . The magnetic Saturation value of GO-Fe 3 O 4 -APTES was 30.6 emu g −1 and the S-like magnetization of all the samples shows super paramagnetic in nature. Due to magnetic nature adsorbent, it could be easily separated from aqueous solution. GO-Fe 3 O 4 -APTES material was highly selective for Chromium (VI) removal from aqueous solution. About 91% of Chromium (VI) was removed at pH 3, 160 rpm of shaking speed, 0.3 g l −1 of adsorbent dose and 10 h of contact time. The adsorption process of Chromium (VI) on GO-Fe 3 O 4 -APTES follows Pseudo-second-order kinetic and Langmuir isotherm model because of high coefficient of determination value (R 2 = 0.99). The maximum adsorption capacity ( q m ) of GO-Fe 3 O 4 - APTES was observed at 60.53 mg g −1 . The synthesized material was desorbed with 0.5 M NaOH and recycled up to five cycles. After five cycles, the removal efficiency of Chromium (VI) possesses high efficacy towards GO-Fe 3 O 4 -APTES. Mechanistically, adsorption of Chromium (VI) follows strong electrostatic attraction between adsorbate and adsorbent. GO-Fe 3 O 4 -APTES has potential adsorbent for the adsorption of Chromium (VI) in waste water treatment. Furthermore, the GO-Fe 3 O 4 -APTES were tested for antibacterial properties against gram negative ( Escherichia coli) and gram positive ( Bacillus subtilis) bacterial strain. The synthesized material responds positively towards antibacterial activity.