Applied Surface Science

• Graphene oxide is synthesized by the Modified Hummers’ Method. • GOs were reduced by Hydrazine hydrate, Heating and Voltage Application. • The materials were characterized by XRD, FTIR, Raman, UV-Vis and SEM-EDX. • The bandgaps are 3.34eV (GO), 2.96eV (HrGO), 2.68 eV (TrGO) and 2.54eV (VrGO). • EDX analysis of Voltage Reduction shows maximum carbon to oxygen ratio C/O ~4. • Categorically reported the correlation study between C/O ratio and Bandgap. In the present investigation we report a comparative study of Graphene Oxide (GO) in regard to its bandgap variations arising due to different reduction methods such as thermal reduction (Heating), electrical reduction (Voltage Application) and chemical reduction (Hydrazine hydrate). This study reveals that among the GO three reduction method studied the voltage application is the most efficient one. It is found that band gap increases with decreasing carbon to oxygen (C/O) ratio and is found to be maximum, i.e. ~4, for the case of GO reduced via voltage application reduction method. The GO for the present study was synthesized by modified Hummer’s Method in four batches out of which the three obtained solutions were reduced by thermal reduction, Voltage application and Hydrazine hydrate. The four resultant materials were investigated by XRD, FTIR, UV–Vis, SEM-EDX and Raman analysis. The variation of band gap of GO and reduced graphene oxide (rGO) was found to be GO 3.34 eV , TrGO (Heating) 2.96 eV, HrGO (Hydrazine) 2.68 eV and VrGO (Voltage application) 2.54 eV, respectively.

Investigation of bandgap alteration in graphene oxide with different reduction routes