Template synthesis of boron nitride nanotubes over iron impregnated mesoporous silica MCM-41 by chemical vapor deposition technique

BN nanotubes were successfully grown over iron impregnated MCM-41 at a relatively low temperature of 750oC for 1 hour by CVD technique. BN nanotubes were obtained after the purification procedure including HCl and HNO3 treatments to remove impurities. SEM image showed the formation of nano-fibrous network BN structures in the diameter range of 20 nm to 40 nm. Both XRD and FTIR characterization results supported the formation of h-BN and c-BN nanostructures. Oxidative TGA results indicated that the synthesized BN nanostructures were thermally stable at temperatures higher than 550oC. Hydrogen storage measurements via IGA showed that BNNTs could adsorb 0.85 wt% hydrogen which was two times larger than for commercial CNTs

The conversion of low-rank Kilyos coal to nitrogeneous fertilizers

The aim of this work is to convert the low-rank Kilyos coal to a material that could be used as a nitrogenous fertilizer. Incorporation of nitrogen into this Kilyos coal was accomplished by oxidative ammoniation, which was a two-step process involving oxidation with nitric acid followed by a treatment by ammonia. The nitrogen content of the raw coal increased from 0.8% to 8.3-9.3% after ammoniation process. Trace element concentrations in the nitro-coal, humic acid, and oxy-ammoniated coal samples were within the acceptable ranges to be used as nitrogenous fertilizer. Therefore the oxy-ammoniated products could be considered as high-value fertilizers

Effect of reaction temperature and catalyst type on the formation of Boron nitride nanotubes by chemical vapor deposition and measurement of their hydrogen storage capacity

Boron nitride nanotubes (BNNT) were synthesized over both Fe3+ impregnated MCM-41 (mobil composition of matter no. 41) and Fe2O3/MCM-41 complex catalyst systems at relatively low temperatures for 1 h by the chemical vapor deposition technique in large quantities. The formation of BNNT was tailored at different reaction temperatures by changing catalyst type. The use of Fe3+-MCM-41 and Fe2O3 as a complex catalyst system led to thin and thick tube formations. The diameters of BNNTs were in the range of 2.5-4.0 nm for thin tubes and 20-60 nm for thick tubes. The thin tube formation originated from the growth of BNNT over Fe3+-MCM-41 due to its average pore size of 4 nm. Higher reaction temperatures caused both BNNT and iron-based side product formations. The hydrogen uptake capacity measurements by the Intelligent Gravimetric Analyzer at room temperature showed that BNNTs could adsorb 0.85 wt % hydrogen which was two times larger than that for commercial carbon nanotubes