A facile method was demonstrated for the one-step synthesis of reduced graphene oxide (rGO) from graphite oxide (GO) using a camphor assisted combustion (CAC) process. Analysis of samples was carried out using FT-IR, XRD, TGA, Raman, BET, SEM and TEM techniques. The electrochemical properties of the rGO samples derived through the CAC process were determined using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy. It has been observed that the specific surface area and porosity of the rGO samples decrease with the increasing concentration of camphor during the CAC synthesis process. Thus, different mass ratios of GO and camphor such as 1 : 12, 1 : 16, and 1 : 20 in the CAC process yield rGO samples having surface areas (SBET) of 313.3, 297.5 and 177.4 m2 g-1. The pore volumes of the respective samples are 0.44, 0.45 and 0.23 cm3 g-1, respectively. The rGO derived using the 1 : 12 mass ratio of GO and camphor (rGO-12C) exhibits a high specific capacitance of 241 F g-1, which is significantly higher than that observed for chemically reduced graphene oxide (rGO-CR), which exhibits a specific capacitance value of only 153 F g-1. The capacitance retention of rGO-12C was found to be 98% even after 1000 galvanostatic charge-discharge (GCD) cycles, suggesting its potential applications in electrochemical energy storage.

ARTICLE This journal isGraphene decorated with Fe clusters is proposed to be a possible alternative catalyst for the hydrogenation and dehydrogenation reactions of MgH2. In particular, graphene decorated with Fe clusters is effective for both the hydrogenation and dehydrogenation processes of MgH2. The change in enthalpy and entropy values of hydrogen absorption determined for MgH2 with 5wt.% graphene decorated Fe cluster are -50.4 ± 2.9 kJmol −1 H2 and 99.8 ±5.2 JK −1 mol −1 H2, respectively. This is significantly lower than the well-established metal catalysts and the nano-interfacial confined MgH2. Moreover, the graphene decorated with Fe clusters helps the fast rehydrogenation kinetics of MgH2, which reabsorbed 90% of the total reabsorption capacity in less than 4 minutes at 300°C and 20 atm. In addition, TEM analysis reveals that MgH2 particles are covered by graphene with Fe clusters, resulting in the reduction of grain growth. Density functional theory shows that defects of graphene act as the active sites for dehydrogenation of MgH2 while Fe clusters reduce the adsorption of dissociated H atoms, resulting in low temperature dehydrogenation. Thus, graphene decorated with metal clusters could open up a new way of designing a new type of catalysts which could replace transition metal catalysts. ARTICLE This journal is ARTICLE This journal is ARTICLEThis journal is

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