TiO_2-NTs/rGO复合材料的制备及电化学性能

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。

Preparation and Electrochemical Performance of TiO2-NTs/rGO Composite

The precursor of titanium dioxide nanotubes(TiO2-NTs) was obtained by alkaline hydro-thermal approach ,which was supported by graphene oxide to form titanium dioxide nanotubes/re-duced graphene oxide composite(TiO2-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 TiO2-NTs in composite is TiO2 (B) with diameter of about 25-30nm .Compared with pure TiO2-NTs ,the rate performance and cycle life of composite are improved remarkablely by loading on graphene .When discharged at the rate of 1C (335mA/g ) ,the initial dis-charge capacity of TiO2-NTs/rGO and TiO2-NTs are 258 .5mAh/g and 214 .9mAh/g ,respectively . The charge transfer resistance of composite is smaller than pure TiO2-NTs characterized by electro-chemical impedance spectroscopy .