碳热还原制备单晶TiC纳米纤维

Single-crystalline TiC nanofibers synthesized by carbothermal reduction

钛酸四丁酯为前驱体,醋酸纤维素(CA)为载体,N,N-二甲基甲酰胺(DMF)/丙酮1∶2(v/v)为溶剂,通过静电方法制备直径为(678±154)nm TiO2/CA复合纳米纤维。在0.1mol/L NaOH/乙醇中水解,TiO2/CA复合纳米纤维转变为TiO2/纤维素复合纳米纤维。在氩气条件下通过碳热还原TiO2/纤维素纤维制备得到单晶TiC纳米纤维。通过扫描电镜、透射电镜和XRD表征纤维的形貌及其晶相组成。实验结果表明:1000℃煅烧得到直径为(424±65)nm纤维,且每根纤维由许多具有规整晶体外形的颗粒堆积而成。温度升高纤维发生一定程度的熔融粘接。XRD表明纤维为立方晶系TiC结构。选区电子衍射出现明显周期排列的二维衍射点,表明制备的TiC为单晶。

TiO2/acetate cellulose（CA） composite nanofibers with diameters of （678 ± 154）nm were fabricated via the electrospinning technique using titanium isopropoxide as precursor, cellulose acetate as carrier, and DMF/aeetone 1：2 （v/v） mixtures as the cosolvent. After treated with 0. 1 mol/L NaOH/ethanol solution,TiO2/CA composite nanofibers were transformed into TiO2/cellulose composite nanofibers. Single crystalline titanium carbide（TiC） nanofibers with diameter of （424± 65）nm were synthesized via carbothermal reduction in an Ar flow. The structure and morphology of TiC were char- acterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results showed that TiC nanofibers with diameter of （424_＋65）nm were obtained by heating at 1000℃. Each fiber was composed of structured grain-like particle. Moreover,nanofibers were melting and adhered together with increasing heating temperature. XRD indi- cated that nanofibers were the structure of cubic TiC. Selected-area electron diffraction presented two-dimensional arranged periodically diffraction point,which indicated that TiC nanofibers were single crystalline.