Borophene–graphene oxide: synthesis, characterization and catalytic application

Abstract

We report the synthesis and physical investigation of a borophene–graphene oxide composite material. The synthesis of borophene was carried out by the liquid-phase exfoliation of boron powder, while graphene oxide was synthesized by the Hummers’ method from graphite. Finally, the composite material borophene–graphene oxide (B–GO) was obtained using a thermal method. The loss of defective sites and creation of new defective sites were confirmed by Raman spectroscopy. According to the DTA and Raman analysis, the oxidation of borophene to either B₂O₃ or BCO₂ was hindered by GO in B–GO. Further, the roughness of B–GO (2.18 nm) was found to be higher than that of GO (1.79 nm) based on atomic force microscopy (AFM). The significant change in the functional groups of GO and the formation of B₂O₃ during the synthesis of B–GO were explained using XPS spectroscopy. Further, morphological studies of GO and B–GO were carried out using SEM and TEM analysis. The catalytic efficiency of the prepared materials was evaluated in the hydrogenation of esters of fatty acids (biodiesel), and B–GO exhibited better catalytic activity than the parent materials of borophene and GO. Remarkably, the I_D/I_G ratio increased significantly in B–GO (from 0.79 to 1) and it decreased in pure GO (from 0.83 to 0.70) after the recyclability test.