以天然椰壳为碳源制备硼碳氮微米线

Synthesis of Boron Carbonitride Microwires Using Natural Cocoanut Shell as Carbon Source

首次以天然椰壳为碳源,高温下在流动氨气中用氯化铁(FeCl_3)对无定型硼粉和椰壳进行退火,大规模合成了硼碳氮(BCN)微纳米结构,即由纳米片包覆竹节状纳米管组装而成的微米线。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶红外光(FTIR)、X射线光电子能谱仪(XPS)以及荧光光谱仪(PL)等手段对所得微米线进行了表征。结果显示,微米线的直径约为200～600 nm,纳米片的平均厚度小于20 nm。纳米片大多是以弯曲和皱折的形态分离的。微米线由B、C、N元素组成,计算出B、C、N的原子比为11. 4∶1∶9. 2。提出了汽液固(VLS)和汽固(VS)相结合的生长机理并对B_(11.4)CN_(9.2)微米线的形成进行了研究。初步讨论了反应温度对微米线的影响。

Boron carbonitride micro-nano structures were synthesized by annealing amorphous boron powder and coconut shell with ferric chloride (FeCl 3) in flowing ammonia at high temperature for the first time by using natural coconut shell as carbon source, and the microwires were consisted of nanotubes covered with nanosheets. The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and fluorescence spectrometer (PL). The microwires have a diameter of about 200-600 nm and the nanosheets have an average thickness of less than 20 nm. The nanosheets are separated, showing a bending and crumpling morphology. The microwires are composed of elements of B, C and N, and the calculated atomic ratio of B, C and N is 11.4∶ 1∶ 9.2. The formation of this B 11.4 CN 9.2 microwires were studied and the growth mechanism of vapor-liquid-solid (VLS) and vapor-solid (VS) interaction was proposed. The effects of reaction temperature on the formation of BCN microwires were discussed preliminarily.