Structural, Optical, and Magnetic Properties of Nitrogen-Doped Graphene Oxide Synthesized by Hydrothermal Method

Abstract

The study examines how different nitrogen doping concentrations affect hydrothermally synthesized graphene oxide's properties using various analytical techniques. Two analytical spectroscopic techniques were used to investigate UV-Visible spectroscopy in dispersed samples, namely bromo phenol blue (BPB) and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The results showed that the doped graphene samples absorb most light in the visible range between 476 and 568 nm in the presence of BPB, and the band gap values obtained using Tauc's formalism ranged from 2.65 to 4.03 eV. In the presence of DDQ reagent, the formation of charge transfer complexes led to sharp absorption peaks in the ultraviolet region around 310 nm wavelength and a range of energy band gap values between 3.77 and 3.98 electron volts. Empirical relations-based calculation of the refractive index (n) for nitrogen-doped graphene displayed optical absorption potential in the visible and UV ranges. Pyrrolic-N bonding dominance in samples was shown by X-ray photoelectron spectroscopy. The VSM results demonstrated that the sample with the highest percentage of Pyrrolic-N exhibited the highest saturation magnetization (0.23 emu/gm) and coercive field (66.6 H Oe). The improved magnetic properties and optical band gap values observed in nitrogen-doped graphene oxide make them promising materials for use in magneto-optical devices.