TiO2-NTs/rGO复合材料的制备及电化学性能

Preparation and Electrochemical Performance of TiO_2-NTs/rGO Composite

通过碱液水热法制备TiO_2纳米管(TiO_2-NTs)前驱体,并将其与氧化石墨烯复合得到二氧化钛纳米管/还原氧化石墨烯(TiO_2-NTs/rGO)复合材料。利用X射线衍射仪(XRD),透射电子显微镜(TEM),电化学测试等分析技术对复合物进行表征。结果表明:复合物中TiO_2-NTs晶相为B型(TiO_2(B)),其管径约为25~30nm;与单纯TiO_2-NTs相比,石墨烯负载的TiO_2-NTs的倍率性能和循环性能都得到显著改善,在放电倍率为1C(335mA/g)时,TiO_2-NTs/rGO和TiO_2-NTs首次放电容量分别为258.5mAh/g和214.9mAh/g;电化学阻抗谱测试显示,复合材料的电荷转移电阻明显小于纯相TiO_2-NTs。

The precursor of titanium dioxide nanotubes(Ti02-NTs)was obtained by alkaline hydro-thermal approach,which was supported by graphene oxide to form titanium dioxide nanotubes/re-duced graphene oxide composite(Ti02-NTs/rGO).The composite was characterized by X-ray diffrac-tion(XRD),transmission electron microscope(TEM)and electrochemical measurements.The results show that the crystalline phase of Ti02-NTs in composite is Ti02(B)with diameter of about25-30nm.Compared with pure Ti02-NTs,the rate performance and cycle life of composite are improved remarkablely by loading on graphene.When discharged at the rate of lC(335mA/g),the initial dis-charge capacity of Ti02-NTs/rG0and Ti02-NTs are258.5mAh/g and214.9mAh/g,respectively.The charge transfer resistance of composite is smaller than pure Ti02-NTs characterized by electro-chemical impedance spectroscopy.