Electrochemical hydrogen storage of expanded graphite decorated with TiO2 nanoparticles

The electrochemical hydrogen storage of expanded graphite (EG) decorated with TiO2 nanoparticles (NPs) calcined at different temperatures has been investigated with the galvanostatic charge and discharge method. The TiO2 NPs are deposited on and between the graphene-like nanosheets of EG by a sol-gel method. The morphology, structure, composition, and specific surface area of the samples were characterized. The electrochemical measurement reveals that the EG decorated with TiO2 NPs calcined at 500 °C has a discharge capacity of 373.5 mAh/g which is 20 times higher than that of pure EG and quite appealing for the battery applications. The mechanism of enhancement of the electrochemical activity for the TiO2-decorated EG could be attributed to the preferable redox ability and photocatalytic property of TiO2 NPs.

► Deposited TiO2 NPs on and between the graphene-like nanosheets of EG.
► EG decorated with TiO2 NPs has a discharge capacity of 373.5 mAh/g.
► The discharge capacity is 20 times higher than that of pure EG.
► Electrochemical activity is mainly due to the preferable redox ability of TiO2 NPs.