TiO₂ nanopaticle was synthesised by sol-hydrothermal using titanium isopropoxide as the precursor. The effects of synthesis conditions on grain size, crystallinity and phase transformation between phasepure rutile and phase-pure anatase, were analyzed by TEM and XRD. It was revealed that crystal-type, crystallinity and crystal-size (from 10-20nm to 120nm) of TiO₂ nanoparticles could be controlled by the pre-thermal treatment, hydrothermal temperature and concentration of the precursor. A paste, made from the nanoparticles and water, and by a doctor-blade technology which could control the thickness of the film were utilized to make a Dye-Sensitized Solar Cell (DSSC), which achieved a photoelectric conversion efficiency of 7.33%, as a result of the phase-pure anatase, appropriate grain size and favorable crystallinity of the TiO₂ nanoparticles. It exceeded those DSSC’s efficiencies made from the commercial paste or P25 paste.

Sodium dodecyl sulfate (SDS) and copper oxide both were used to modify titanium dioxide photocatalytic catalysts. SDS was used to prepare hydrophobic titanium dioxide. Copper oxide was used to modify the visible light absorption capacity of titanium dioxide. FTIR, UV-Vis and 3-D fluorescence spectra methods were used to characterize the modified titanium dioxide photocatalytic catalysts. The modified titanium dioxide catalysts were used to treat nitrobenzene wastewater. Four factors including pH, initial nitrobenzene concentration, catalysts dosage and light intensity, were researched in a nitrobenzene degradation system that was treated under visible light. FTIR characterization shows that CC and CHfunctional groups appear on the surface of the catalysts. UV-Vis characterization shows that the catalysts modified by copper oxide have excellent visible light response capacity and their absorption edges reach or exceed 830nm. 3-D fluorescence spectra shows that holeelectrons are separated well after copper oxide and/or SDS is added. The speed of nitrobenzene degradationis fastest when pH is 9, the initial nitrobenzene concentration is 500mg/L, the catalyst dosage is 0.2g/L, and light intensity exceeds 2000μW/cm². A kinetic model is established based on the results. The relative errors of the kinetic constants obtained by the model are between -16.5% and approximately -4.5% with low initial nitrobenzene concentrations, and between -11.3% and approximately 4.6% with high initial concentrations.

H₂SO₄-modified TiO₂ particles were prepared using a sol-gel method followed by impregnating the dry gels with sulphuric acid and were used to fabricate an electrorheological (ER) fluid with high ER activity. The as-synthesized H₂SO₄-modified TiO₂ particles were characterized by fourier transform infrared (FT-IR), X-ray diffraction (XRD), BET N₂ adsorption-desorption isotherm analysis, and the ER effect and dielectric spectra of the ER fluids were measured. The results show that H₂SO₄-modified TiO₂ particles have smaller size of crystal grains and higher specific surface area due to the restraint of SO₄^2- from the grain growth. Under the same measured condition and electric field strength of 3kV/mm, the ratio of fieldinduced shear stress to zero field shear stress (τ_E/τ₀) of TiO₂ particles is 80, while that of H₂SO₄-modified TiO₂ particles is more than 500. The observed ER performances are reasonably explained by the stronger interfacial polarization, which is brought by the specific structures of the H₂SO₄-modified TiO₂ particles.

The highly ordered TiO₂ nanotube arrays were fabricated by anodic oxidation of titanium foil. The influences of electrolyte characteristic and concentration as well as anodization time on the morphology of TiO₂ nanotube arrays were studied, and the growth mechanics were analyzed. Results show that regular ordered TiO2 nanotube arrays can be prepared in hydrofluoric acidic solution, the pipe diameters are uniform and the surfaces are smooth, but the lengthes are limlited in the range from 300nm to 350nm. TiO₂ nanotube arrays and nanorod arrays can be obtained in high concentrate hydrofluoric acidic solution. TiO₂ nanotube arrays with high slenderness ratios and rough surfaces are prepared in sodium fluoride and sodium sulfate electrolyte with lengths of 700nm which are longer than those prepared in hydrofluoric acidic electrolyte. TiO₂ nanotube arrays with pipe diameters of about 150nm can also be prepared in glycol, ammonium fluoride and water ethyleneglycol electrolyte, the lengths of which can reach up to 6μm.

Using glucose and commercial activated carbon (AC) were as starting material, carbon sphere was synthesized on the surface and interior of pores of AC by solvothermal method and a new composite carbon material was prepared which was rich in oxygen-containing functional groups. Nitrogen adsorption isotherm and SEM were used for the observation of pore structure and surface morphology. FTIR and XPS were used for oxygencontaining functional groups analysis. Cr(VI) was used as inorganic metal ion model for adsorption capacity measurement. The results show that micrometer carbon sphere rich in oxygen-containing functional groups can be effectively anchored on the surface of AC. The obtained carbon composites exhibit remarkable enhanced adsorption capacity for Cr(VI) in terms of per mass or per surface area, which is approximately 4 and 95 times of that for ACraw, respectively. The size and dispersion of carbon spheres are dependent on the concentration of glucose, as well as the generated oxygen-containing functional groups. With the increase of glucose concentration, the porosity decreases and the number of oxygen-containing functional groups increases and C—OH becomes dominant.

Micro-coiled carbon fibers were prepared by chemical vapor deposition method (CVD), and aligned via a device designed for executing action with mechanical drawing. Optical microscope was performed to characterize the morphology and aligned state of the fibers. The AC impedance characteristics (impedance |Z| and phase angle θ) of the aligned carbon coils were studied. The results show that impedance and phase angle of the carbon coils keep stable at low frequency, but decrease rapidly with the frequency increasing at high frequency area (f>10kHz). Furthermore, the aligned fibers are sensitive to their extending states, and their impedance increases with the extending length prolonging. The study is useful to develop the technique of micro-circuits and micro-sensor based on carbon micro-coils.

Controlled growth of ZnO quasi-one-dimensional nanostructures with different morphologies were accomplished by thermal oxidation of zinc vapor in a vapor deposition system. The products include uniform nanobelts with different growth directions, [011-0] and [21-1-0] orientated nanobelts with nano-teeth on one side, micro-scale comb-like nanobelts and faceted fibers with periodic junctions constructed by hexagonal prisms or octagonal prisms along [011-0] and [21-1-0] directions, and so on. The morphologies and the crystal structures were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with electron backscatter diffraction (EBSD), high-resolution transmission electron microscope (HRTEM) in details. The basic configurations constructed the multiple ZnO nanostructures were discovered, the formation mechanism and the morphology multiformity of ZnO crystals were analyzed. The evolution processes of these quasi-one-dimensional configurations were discussed based on the crystal growth mechanisms. It is found that the ZnO fibers with periodic junctions and the comb-like nanobelts have an identity of crystal structure with the nanobelts.

Aluminum oxynitride (AlON) powders were prepared by solid-state reaction processing with α-Al₂O₃ and AlN as starting materials in nitrogen atmosphere. The effects of reactive temperature, holding time, and Al₂O₃/AlN ratio on the resultant phase compositions were investigated systematically by XRD. In addition, the reactive mechanism was tentatively explored. The experimental results indicate that the solid-state reaction for AlON is mostly controlled by thermodynamics and the dynamic factors are also important to the reaction. The reaction can not be thoroughly processed neither only by prolonging holding time at lower reactive temperature nor only by increasing reactive temperature in a shorter holding time. Both reactive temperature and holding time are crucial to the reactive progress. By diffusing AlN into Al2O3 lattice, O-riched AlON formations begin between 1600℃ and 1650℃, and finish at about 1750℃. Above 1800℃, O-riched AlON converts into Nriched AlON by further diffusing remnant AlN into Al2O3 lattice. Pure AlON is prepared by the solidstate reaction of Al2O3 and AlN at 1950℃ in nitrogen atmosphere for 4h.