Elucidating Evidence for the In Situ Reduction of Graphene Oxide by Magnesium Hydride and the Consequence of Reduction on Hydrogen Storage

The current study highlights important information regarding how graphene oxide (GO) additive interacts with magnesium hydride (MgH2) and transforms to reduced graphene oxide (rGO). A mild reduction occurs during mechanical milling itself, whereas a strong reduction of GO happens concurrently with the oxidation of Mg formed during the dehydrogenation of MgH2. Owing to the in situ transformation of GO to rGO, the dehydrogenation temperature of MgH2 reduces by about 60 degrees C, whereas the hydrogen ab/desorption reaction kinetics of MgH2 increases by two orders of magnitude and the dehydrogenation activation energy decreases by about 20 kJ/mol. We have thoroughly scrutinized the transformation of GO to rGO by differential scanning calorimetry (DSC), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM) techniques. Interestingly, the GO to rGO transformation triggered by magnesium hydride in the current study further paves the way for the facile preparation of rGO- and MgO-decked rGO composites, which are important materials for energy storage applications.

Automated summary

The current study investigated the interaction between graphene oxide (GO) additive and magnesium hydride (MgH2), leading to the transformation to reduced graphene oxide (rGO). The results showed that the in situ transformation of GO to rGO reduced the dehydrogenation temperature of MgH2, increased the hydrogen ab/desorption reaction kinetics, and decreased the dehydrogenation activation energy. The study also demonstrated the potential of using magnesium hydride to trigger the GO to rGO transformation for the preparation of rGO and rGO composite materials, which are important for energy storage applications.