Synergic Effects of Chemical Reduction and Nitrogen Doping on the Structural and Electrical Properties of N-ZnO/N-rGO Nanostructures

In this study, the synthesis, followed by a detailed evaluation of the structural, optical, and electrical properties of the N-ZnO/N-rGO nanocomposite prepared using a one-step low-temperature hydrothermal process, is reported. By employing N, N-dimethylformamide (DMF) as the reducing agent and urea as the nitrogen precursor, simultaneous reduction and nitrogen doping are achieved in the nanocomposite. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman measurements are used for the structural evaluation. The formation of composites is verified using the ZnC/ZnOC bonds in the XPS. The nitrogen doping in the nanocomposites varies from 0.8% to 1.8%. The major nitrogen moieties observed here include pyrrolic N, pyridinic N, and graphitic N. The electrical response is measured using current–voltage characteristics, and enhanced conductivity was observed in the sample with the highest percentage of pyrrolic N. This is attributed to the superior electron transport mechanism of pyrrolic N in the graphene structure. The current response is found to increase from 2 to 10 μA from ZnO/rGO to N-ZnO/N-rGO nanocomposite. The integration of N-rGO support with extensively doped pyrrolic end groups for the N-ZnO nanoparticles has been found to improve the conduction mechanism and is hence promising for many applications.