Facile synthesis and characterization of a reduced graphene oxide/halloysite nanotubes/hexagonal boron nitride (RGO/HNT/h-BN) hybrid nanocomposite and its potential application in hydrogen storage

The hydrogen storage performance of hybrid nanocomposites composed of reduced graphene oxide, acid treated halloysite nanotubes and hexagonal boron nitride nanoparticles (RGO/A-HNT/h-BN) was studied. A modified Hummer's method and sonication assisted liquid-phase exfoliation technique were adopted for the synthesis of GO and preparation of hybrid nanocomposites (RGO/A-HNT/h-BN), respectively. The prepared hybrid nanocomposites were analyzed using X-ray diffraction (XRD), micro-Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Thermo Gravimetric Analysis (TGA). Using a Sieverts-like hydrogenation setup, the hydrogen storage properties of RGO/A-HNT/h-BN hybrid nanocomposite were examined. The RGO/A-HNT/h-BN hybrid nanocomposite exhibits 3.3 wt% of storage capacity at 50 degrees C and 100% desorption of stored hydrogen was observed in the temperature range of 119-143 degrees C. The average binding energy of stored hydrogen was found to be 0.32 eV and it lies in the recommended range of US-DOE targets. The reusability test confirms 93.3% storage capacity for the fifth cycle of hydrogenation. Hence it is expected that the prepared RGO/A-HNT/h-BN hybrid nanocomposite may serve as a promising hydrogen storage medium for fuel cell applications.