Synthesis of boron-doped reduced graphene oxide as electrode material for supercapacitor applications

Graphene-based materials are majorly utilized as electrode in supercapacitors due to its tunable electrochemical, structural, and electrical properties. Doping of graphene-based materials with different heteroatoms such as boron, nitrogen, and sulfur is an effective way for improving the capacitive properties. Among various routes, chemical doping is an easy and economic approach. Here, we are reporting bulk synthesis of boron-doped reduced graphene oxide (B-rGO and r-BGO) as an electrode material for supercapacitors using boric acid (H3BO3) as boron source. In r-BGO, GO is first reacted with boric acid and then reduced, whereas in B-rGO boron doping is done after reduction from GO to r-GO. The structural properties of boron-doped samples in comparison with graphene oxide (GO), graphite, and reduced graphene oxide (r-GO) have been studied by XRD, Raman, and FETEM analyses. The boron doping of similar to 9% has been confirmed by EDAX analysis. The r-BGO samples are highly crystalline in nature, whereas B-rGO is amorphous. An increase in interlayer spacing from 0.23 nm for GO to 0.28 nm has been observed in r-BGO. This could be due to intercalation of boron atom in the lattice. FTIR studies also confirm the doping due to presence of B-C and B-O bond. We have reported an increased specific capacitance of 326.56 +/- 3.1 F/g for r-BGO compared to GO (137.88 +/- 1.8 F/g) and r-GO (108.85 +/- 1.6 F/g).