Post-synthesis treatment of graphene oxide/silica particles nanocomposite with piranha acid for functionalization

Abstract

The discovery of 2D materials has led researchers to a broad material platform. Their excellent physical, chemical and electrical properties along with the layered structure have found applications in various fields. However, these materials also have limitations and functionalisation is one of the mechanisms that improves their properties. In our previous work, we observed surface-enhanced Raman spectroscopy (SERS) after covalent attachment of protein to the graphene nanocomposite where piranha acid was used to generate the functional groups. The current work describes the synthesis and characterisation of a graphene oxide-silica particle nanocomposite after piranha acid treatment at different time intervals. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy were performed to indicate structural changes which facilitated the protein attachment. The SEM and TEM results indicated that the sample which was piranha acid activated for 3 min displayed better arrangement of silica particles on the graphene sheets with exposition of the highest net surface area in the graphene sheet, compared to the other samples and determined to be the best functionalised nanocomposite for further applications. Morphological instability of the graphene sheets and clustering of silica particles were observed in the samples treated for more than 3 min. Interestingly, the same degree of graphitisation was observed in all the samples when I D /I G ratios {(≤0.99) ≠ 0} were determined by Raman spectroscopy.

Graphene Oxide-Induced Prototropism and Enhancement of Fluorescence Yield of Organic Molecules in Solutions: Recent Advances

“…Defect activated combination of phonons with various moments explains the D + D' peak (∼2950 cm –1 ) . The I (D)/ I (G) ratio of GO powder is 0.97, resonating with the literature value. , The absorption spectra of GO in ACN exhibit two peaks at ∼230 and ∼300 nm. In the case of ACE, the peak is generated at ∼315 nm.…”

“…33 The I(D)/I(G) ratio of GO powder is 0.97, resonating with the literature value. 34,35 The absorption spectra of GO in ACN exhibit two peaks at ∼230 and ∼300 nm. In the case of ACE, the peak is generated at ∼315 nm.…”

ZnO/Ag/Reduced Graphene Oxide Nanocomposite as a Conductive Layer for Electrochemical Monitoring of Candida albicans Biofilm Formation and Dynamics

“…The (ZnO/Ag/RGO) nanomaterial was synthesized using a one-pot hydrothermal method, as described in our previous publications. , Initially, graphene oxide (GO) was prepared via a modified Hummer’s method, followed by the preparation of the nanocomposite. Briefly, a vessel containing a 0.01 M ZnAc 2 solution received dropwise additions of 6.67 M NaOH, 0.01 M AgNO 3 solution, and a (1 mg/mL) stock solution of GO in a sequential manner.…”