A new approach to synthesize ammonium uranate decorated reduced graphene oxide nanosheets and their performance in electrochemical hydrogen storage

Abstract

In this research, the ternary solid phase of UO3⋅NH3H2O has been successfully synthesized via a simple and novel hydrothermal method under ammonia atmosphere, and identified as an ammonium uranate. Moreover, the decorated reduced graphene oxide network with ammonium uranate, UO3/rGO nanocomposite, was prepared and used to hydrogen sorption and storage. On the other word, for the first time, the electrochemical hydrogen storage behavior of the uranium compounds was evaluated by chronopotentiometry technique. Additionally, in order to further investigate the effect of ammonium uranate nanoparticles on the hydrogen storage property of UO3/rGO, two ratios of UO3:rGO in the as-made nanocomposites, 1:3 (UrGO3) and 1:10 (UrGO10), were studied. On this basis, the maximum discharge capacity was observed for the UrGO3 at 16,343 mAh/g after 20 cycles. The FE-SEM images indicated the UrGO3 nanosheets consist of the hierarchical plate-like pores, in a good agreement with BET analysis. According to the results, UO3 is introduced as a good candidate to improve the performance of electrochemical hydrogen storage on the graphene surface.