Papers by Author: Fei Huang

Abstract: An efficient method for functionalizing carbon nanotubes (CNTs) is reported, which combined HF corrosion with sulfuric acid and nitric acid for further oxidation. The X-ray diffraction and transmission electron microscopy are employed to investigate the physic-properties of the prepared catalysts. Cyclic voltammetry and chronoamperometry methods are used to study the performance of the prepared catalysts. CNTs further treated with H2SO4 and HNO3 mixed solutions with the volume ratio of 1 to 3, heating at 100 oC for 2 h, used as catalysts supports exhibit significantly improved performance towards ethanol oxidation in alkaline solutions in comparison with other decorated CNTs. The reason could be attributed to the oxygen-contain functional groups on CNTs surface can efficiently improve the interaction between CNTs and metallic particles in catalysts.

Abstract: Hierarchical ZrO2 nanorods have recently received considerable attention due to their special physical and chemical properties. However, traditional preparation methods are involved in expensive equipment, complicated process and high production cost. Here we report a simple hydrothermal approach to prepare hierarchical ZrO2 nanorod. The results show that as-synthesized products are composed of many nanorods with 80~150 nm in diameter and 15~20 μm in length. After annealing, the final product was involved into hierarchical monoclinic ZrO2 (m-ZrO2) nanorods, namely, the big nanorod was made up of many small nanorods with 20~30 nm in diameter and 300~500 nm in length. The possible formation mechanism was proposed based on a series of chemical reactions and the natural properties of zirconium.

Abstract: Tungsten trioxide (WO3-x) with different morphologies was synthesized by hydrothermal method. Using a pair of Pt electrodes and Al2O3 ceramics tube as a substrate, NO2 sensing properties of the WO3 products were measured at different working temperatures. And the high sensing properties at low working temperature were also investigated. The results showed that the sensitivity of WO3 product is strongly dependent on morphology and structure. The parallel circuit mode also plays an important role in the NO2 sensing characteristics. The low working temperature can be attributed to the competitive reaction between O2 and NO2 gas. The parallel mode may increase the lifetime of sensor.

Abstract: La doped ZnO nanorods were synthesized via solvothermal technique using Zn(AC)2 and La(NO3)3 as starting materials. The products were characterized by X-ray diffraction (XRD), field scanning electron microscopy (FESEM) equipped with an energy dispersion X–ray (EDX) spectrometer, photoluminescence spectroscopy and UV-vis spectroscopy. The results of XRD in combination with EDS indicated that La was successful doped in ZnO. The obtained La doped ZnO sample exhibited nanorod like morphology and the diameter was about 30 nm. The photocatalytic property of La doped ZnO was evaluated by the variation of the concentration of RhB.

Abstract: Flowerlike bicephalous titanium diboride (TiB2) nanowhisker clusters were fabricated by planetary ball-milling. The pure cleavage theory and crack growth mechanism were used to explain the formation process. The high-resolution transmission electron microscopy and nano electronic beam diffraction show that TiB2 superhard material always has a cleavage plane along the direction of [0001] zone axe and [10 0] zone axe because of its big interplane distance, weak bonding force between planes and low index directions. The flowerlike bicephalous TiB2 nanowhisker can be gained after repeated cleavage under high strains. The discovery could open a new path to fabricate C32 type superhard ceramic nanowhiskers.

Abstract: TiO2/TiB2 heterostructures were successfully synthesized by a facile hydrothermal approach in an aqueous solution of hydrogen peroxide (H2O2). The influence of H2O2 on TiB2-based materials was systematically investigated using X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that TiB2 is prone to oxidize in the presence of H2O2. TiO2/TiB2 heterostructure which high-density anatase-TiO2 stand on the surface can be gained in the presence of H2O2 solvent and the final composition can be controlled by the temperature and time. The investigation may provide a path to further understand the chemical property of TiB2-based materials and synthesis method of heterostructure.

Abstract: SnO2 nanocrystals with various morphologies were synthesized via a hydrothermal method assisting by the surfactant CTAB. The morphologies of the products were significantly dependent on the synthesis conditions. The products were characterized by X-ray diffraction (XRD) and field scanning electron microscopy (FESEM).The results showed products SnO2 nanoparticles and spheres like structure assembled with nanocones were obtained by varying the dosage of CTAB and the concentration of NaOH. The forming process of SnO2 sphere like structure was discussed and the proposed mechanism was put forward in this work.