Termal indirgenmiş grafen oksit ile elektrokimyasal olarak askorbik asit tayini

Merve OKUTAN
2020 Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi  
Highlights: Graphical/Tabular Abstract  Graphene was thermally reduced by flash heat treatment  Functional groups were effectively eliminated when graphene was synthesized  With the T-rGO modified GCE, AA was determined with 0.3 μA mM -1 sensitivity The present work, describe the synthesis of thermally reduced graphene oxide (T-rGO) with high temperature flash heat treatment and its characterization by SEM, XRD, Raman, FTIR, EDX and electrochemistry. The T-rGO and Nafion solution (N117)
more » ... ied glassy carbon electrode (GCE) was directly used for electrochemical sensing of ascorbic acid (AA) in the phosphate buffer solution (PBS). Electrochemical behavior of the modified GCE was identified by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometric techniques. For this purpose, graphene oxide (GO) was synthesized from the synthetic graphite as starting material using by the modified Hummers method. Then, T-rGO was obtained by reducing GO by applying flash and high temperature thermal treatment in an inert gas environment. Figure A. Preparation steps of T-rGO from graphite and electrochemical behavior of T-rGO in Fe(CN)6 3electrolyte Purpose: To minimize the presence of oxygen-containing functional groups between the layers after reduction in graphene synthesis. Investigation of the electrochemical performance of synthesized T-rGO and sensitivity against to AA. Theory and Methods: Graphene was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), fourier transformation infrared (FT-IR) spectroscopy, Raman spectroscopy and X-ray diffraction (XRD) methods to investigate morphology and determine the functional groups in structure. The electrochemical behavior of the glassy carbon electrodes prepared by using T-rGO, in PBS containing AA was investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometric analyzes. Results: While GO was thermally reduced, it was found that the C/O ratio decreased as a result of degradation of oxygenated functional groups in the structure and the distance between planes decreased to 0.37 nm. It was determined that the number of layer is about 3.32 for T-rGO according to XRD analysis. According to the results, the prepared GCE/T-rGO electrode exhibited good sensitivity (0.3 μA mM -1 ) and low detection limit (0.61 μM) of AA with good reproducibility (RSD=6.25%, n=3) and repeatability (RSD=2.14%, n=3). In addition, the GCE/T-rGO electrode showed good selectivity against the uric acid, dopamine, KCl, NaCl and CaCl2. Conclusion: T-rGO modified electrode was a sensitive and selective sensor against to AA without requiring no further modification with auxiliary chemicals such as Nafion in consequence of reduction method.
doi:10.17341/gazimmfd.645284 fatcat:ta57te6i3jf3zc25rfb6mhb7eu