Preparation of nitrogen and sulphur Co-doped reduced graphene oxide (rGO-NS) using N and S heteroatom of thiourea

Graphene oxide (GO) has been synthesized via modified Hummer's method with graphite powder as a starting material. The synthesized reduced graphene oxide (rGO) was prepared by GO as a precursor. Synthesis of rGO-NS was performed by hydrothermal method using a dopant thiourea as nitrogen (N) and sulphur (S) donors with the ratio of GO: thiourea= 1: 10, 1: 15, and 1: 20 (w/w), respectively. Characterization using Fourier Transform Infra-Red (FTIR) spectroscopy shows several peaks that have an agreement with -OH, C=O, C=C, C-OH, and C-O functional groups for GO and absorption peaks of -OH, C=C, and CO functional groups for rGO with different intensity, while modified materials of variation rGO-NS emerged typical absorptions of -OH, C=C, C=N, C-N, and C-S functional groups. GO and rGO material that have been analysed using X-Ray Diffraction (XRD) shows a dominant peak at 2 theta 10.77 degrees (001) and 24.97 degrees (002), respectively. While the distance between layers (d(spacing)) on rGO (3,56 angstrom) was lower than GO (8,22 angstrom). Compared to rGO, XRD analysis also shows that the addition of N and S on GO structure caused shifting of 2 theta in 23, 73 degrees-24,06 degrees (002) and calculated d(spacing) of rGO-NS is found to be 3,70 angstrom-3,74 angstrom. Morphological observation of rGO-NS using Scanning Electron Microscopy (SEM) shows that rGO-NS is a thin transparent sheets formed because the exfoliation process of GO material.