Electrochemical hydrogen storage of expanded graphite decorated with TiO_2 nanoparticles

摘要

The electrochemical hydrogen storage of expanded graphite (EG) decorated with TiO_2 nanoparticles (NPs) calcined at different temperatures has been investigated with the galvanostatic charge and discharge method. The TiO_2 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 TiO_2 NPs calcined at 500 ℃ 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 TiO_2-decorated EG could be attributed to the preferable redox ability and photocatalytic property of TiO_2 NPs.