Nanocomposites formed by in situ growth of NiDOBDC nanoparticles on graphene oxide sheets for enhanced CO2 and H-2 storage

Abstract

A hybrid composite containing NiDOBDC [Ni-MOF-74 or Ni-2(dobdc)] and graphene oxide (GO) was successfully synthesized using a facile method for enhanced CO2 and H-2 storage. Additional porous spaces were created when the nanocomposite material with a three-dimensional (3-D) architecture was constructed with two-dimensional (2-D) graphene oxide sheets and microporous NiDOBDC nanoparticles. The analysis of gas storage performance reveals that the generation of new porosity resulted in enhanced CO2 and H-2 adsorption. In particular, the NiDOBDC/GO composite with 10 wt% GO loading exhibited the highest CO2 and H-2 storage values, up to 10.5 mmol/g (298 K, 20 bar) and 1.39 mmol/g (298 K, 20 bar), respectively, values that are significantly higher than those of the Ni-DOBDC metal-organic framework. Besides, enhanced CO2/N-2 selectivity was also observed for NiDOBDC/GO composite due to the additional storage sites for CO2. The strategy demonstrated in this work can also be applied to other microporous materials to enhance their gas adsorption properties.