| Hydrogen is one of the most promising future sustainable energy fuels due to its abundance,high energy density,and environmental friendliness.However,the major impediment is that it is difficult to be high-capacity stored within an effective,safe and stable solid-state medium,which restricts its practical application.Hence,the design and synthesis of new hydrogen storage materials with high capacity and excellent cycling stability are extremely desirable.In this paper,we synthesize a series of CoB-graphene and one-dimensional core/shell Co-C hydrogen storage materials through ball-milling methods.The morphology and microstructure of the materials were investigated by SEM,TEM and XRD,etc.In addition,the capacities of hydrogen storage,charge-discharge curves and storage mechanism were studied,respectively.A series of CoB-graphene materials are synthesized by ball-milling method.Frist,different CoB alloys were synthesized in difffernent speed and ball-milling time.Second,in order to investigate the effect of graphene on CoB alloys,we take the ratio between CoB and grapheme at ratio of 2:1,5:1 and 10:1,respectively.And after few hours ball milling process,we get a serials of CoB-graphene samples with mass sandwich-like structure.It shows that the maximum discharge capacity of materials is the one that the ratio is 5:1 and ball-milling time is 10 hours.And the maximum capacity is about 2.87 wt%.A series of one-dimensional CNT/Co and CNF/Co materials are synthesized by ball-milling method.In this work,metal cobalt has been uniformly coated on CNT’s and CNF’s surfaces in nanoscale through a simple ball milling process.Accordingly their X-ray diffraction,scanning electron microscope and transmission electron microscopy measurements clarify the satisfying composite structures.And their electrochemical experimental results demonstrate that the as-obtained CNT/Co and CNF/Co composites have excellent electrochemical hydrogen storage reversibility and considerably high storage capacities of 2.62 wt% and 2.70 wt%. |
