Multi-walled carbon nanotubes (MWCNTs) were grafted with sulfonyl chloride groups using chlorosulfonic acid as a sulfonation reagent, and then the amino-modified multi-walled carbon nanotubes of MWCNT-NH₂ was prepared via the aminolysis reaction. The MWCNT-NH₂ was further reacted with copper phthalocyanine sulfonyl chloride to prepared the complex of MWCNT-Pc. The products were fully characterized by various standard analytical techniques, including scanning electron microscope, transmission electron microscope, infrared spectroscope, UV-Vis absorption spectroscope, Raman spectroscope, X-ray photoelectron spectroscope, thermogravimetric analysis, and cyclic voltammetry. The results indicated that the complex of MWCNT-Pc was fabricated through covalent assembly of MWCNT-NH₂ with copper phthalocyanine, with a copper phthalocyanine molecule for every 38 MWCNT carbons.The thermal stability of the complex of MWCNT-Pc was lower than that of MWCNT-NH₂.The photoelectrode of ITO/MWCNT-Pc fabricated by the method of the spray showed a better photoelectric performance with the photovoltage and the photocurrent were 0.434V and 0.158mA/cm² respectively, and the internal photoconversion efficiency at 320nm was up to 19.8%. Based on the band structure of the complex of MWCNT-Pc, the photoinduced electron transfer process was proposed as follow: firstly the electronic transitions occured in the Pc moiety of MWCNT-Pc, following electrons transferred to MWCNTs and then further passed to the ITO to achieve the charge separation.

Barium ferrite BaFe₁₂O₁₉ (BaM) powders were prepared by using molten salt method. The preparation conditions of samples were investigated in detail, such as annealing temperature, soaking time, molten salt additive amount and Fe³⁺/Ba²⁺ molar ratios. The phase composition, microstructure and magnetic properties of the resultant powders were measured respectively by X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM) and Vibrating Sample Magnetometer (VSM). Formation of BaM started below 750℃ in 0.5NaCl+0.5KCl. Single phase BaM powders were obtained while the Fe³⁺/Ba²⁺ molar ratios was controlled in the range from 10 to 11.5. The SEM results showed that the grains were regular hexagonal platelets when molten salt additive amount R was controlled in the range from 1 to 3. The resultant powders achieved under condition of Fe³⁺/Ba²⁺ molar ratios of 11.5 and calcination temperature of 1000℃ showed the saturation magnetization up to 71.9A·m²/kg, which was quite close to the theoretical value of 72A·m²/kg.

PVP/Sr_1-xLa_xFe_12-xCo_xO₁₉ (x=0-0.5) composite nanofiers were fabricated by Sol-Gel process and electrospinning technique. After high temperature calcination, Sr_1-xLa_xFe_12-xCo_xO₁₉ (x=0-0.5) ferrite nanofibers were successfully obtained. The morphology, phases, structure and magnetic properties of the nanofibers were characterized by Scanning electron microscope(SEM), Transmission electron microscope(TEM), X-ray diffraction(XRD) and Vibrating sample magnetometer(VSM). The results show that the samples have an uniform diameter of 80-150 nm after calcined at 800℃. The Sr_1-xLa_xFe_12-xCo_xO₁₉ (x=0-0.5) ferrite nanofiers all exhibit a hard magnetic performance, and chemical composition have considerable influence on magnetic properties of these ferrite nanofibers. The Sr_1-xLa_xFe_12-xCo_xO₁₉ (x=0-0.5) ferrite nanofiers exhibit M-type strontium ferrites, CoFe₂O₄ phase and LaFeO₃ phase at x≥0.3. The substitutions of La³⁺ and Co²⁺ obviously increase the magnetic properties of the as-prepared samples at x≤0.1, the coercivity(Hc), saturation magnetization(Ms) and remanent magnetization(Mr) of Sr_0.9La_0.1Fe_11.9Co_0.1O₁₉ nanofibers are 432.02 kA/m, 54.7 A·m²/kg, 28.9 A·m2/kg, respectively. The magnetic properties of the fibers increase significantly, compared with that of the Sr_0.9La_0.1Fe_11.9Co_0.1O₁₉ powder samples.

Nonstoichiometric silicon nitride (SiN_x) thin films with silicon nanoparticles were deposited on p-type crystalline silicon and quartz substrates at low temperature (200℃) using ammonia and silane mixtures by plasma enhanced chemical vapour deposition (PECVD). The thin films structure was improved by high-temperature (range 500-950℃) annealing. The photoluminescence (PL) spectroscope, Raman spectra and Fourier transform infrared spectroscope (FTIR) of the SiN_x thin films annealed at different temperatures were investigated at room temperature. The structure, luminescence and bonding configurations of the thin films were analyzed. Raman spectra showed that the silicon nanoparticles embedded in SiN_x thin films were amorphous structure. Two PL spectra bands related to silicon nanoparticles were observed from PL spectra and their peak shifts were the same with increase of annealing temperature. For samples annealed below 800℃, the PL peaks show a blue-shift with increasing annealing temperature, while for the samples annealed over 800℃, an obvious red-shift of PL peaks is observed. Three kind of spectral analyses of the films show that photoluminescence of the thin films was attributed to quantum confinement effect of silicon nanoparticles. These results have valuable implications for the optimization of silicon nanoparticles fabrication process and silicon nanoparticles photoelectric device applications.

To reduce the diffusion resistance, improve the energy efficiency and extend the life of solid oxide electrolysis cells (SOEC), the porosity and microstructure optimization of SOEC cathode support layer were studied. Polymethyl methacrylate(PMMA)was added into the cathode as an alternative of starch for pore formation. The experimental results show that the porosity of cathode reaches 45% with conductivity of 6726 S/cm when the PMMA content is 10wt%. The round micro-pores formed by PMMA are well distributed with an average diameter of about 10 μm, which not only significantly reduce the gas diffusion resistance and increase the mechanical strength of cathode materials, but also improve largely the electrolysis efficiency, stability and hydrogen production performance of the SOEC. After the microstructure modification and optimization of cathode layer, the hydrogen production rate of SOEC using PMMA pore former can reach 175mL/(cm²·h), which is 1.5 times of the hydrogen production rate of starch. Also their steam diffusion resistance reduce 50% at 850℃ and 1.3V electrolysis voltage, which indicates that PMMA is a very promising candidate for the application of SOEC technology.

Oxygen storage material of Ce_0.5Zr_0.5O₂(12wt%)-Al₂O₃(CZA) was prepared by three different methods of coprecipitation, peptization and peptization-coprecipitation. The structure and physicochemical properties of materials were characterized by X-ray diffraction (XRD), N₂ adsorption-desorption, oxygen pulse adsorption (OSC), H2-temperature programmed reduction (TPR) and O₂-programmed desorption (O₂-TPD). The XRD results demonstrate that all the samples have CeO₂-ZrO₂ cubic fluorite and γ-Al₂O₃ after calcined at 1000℃. The results according to N₂ adsorption-desorption show that the sample prepared by peptization-coprecipitation has higher specific surface area (146.2 m²/g), larger pore volume (0.5 mL/g), and the best distribution of the pore size. The results from OSC and H₂-TPR indicate that the sample prepared by peptization-coprecipitation has the best performance of oxygen storage and reduction capacity. At the same time, the influence of different methods on the properties of samples after calcined at 1100℃ are discussed.

Both TiO₂ compact layer (d-TiO₂) and Li-doped TiO₂ compact layer (d-Li-TiO₂) were deposited between nano-TiO₂ and transparent conductive oxide (TCO) for dye sensitized solar cells (DSSC) by the technique of pulsed laser deposition (PLD). XRD pattern shows the compact layers are crystallized in anatase structure. Compared with FTO-based DSSC without compact layer, the open voltage decay measurement shows the novel structure can slow the decay of the open circuit voltage, indicating an effective suppression of back electrons transfer from TCO to the electrolyte by the dense buffer layers. In addition, the interface resistance between the nano-TiO₂ and the TCO falls down due to the reduced energy band-gap of Li-doped TiO₂, which makes it easier to transfer the generated electrons from conducting band of nano-TiO₂ to TCO surface, leading an enlarged short current from 4.2 mA/cm² of FTO-based to 4.8 mA/cm² for that with d-TiO₂ and 6.1 mA/cm² for d-Li-TiO₂, respectively. Thus, the photovoltaic energy conversion efficiency of DSSC based on the Li-doped TiO₂ compact layer enhances as much as 42% compared with that FTO-based DSSC without TiO₂ compact layer.

The (RuO₂/Co₃O₄)·nH₂O composite films electrode used in super capacitor was prepared from isopropanol solution of RuCl₃·3H₂O and Co(CH₃COO)₂ by in-situ thermal decomposition. The micro-    morphology, phase transformation and electrochemical properties were studied by scanning electron microscope, XRD, infrared spectrometer and electrochemical method, respectively. The results show that, the composite films with n(Rn³⁺): n(Co²⁺)=1:3 exhibit the best performances after heat treatment at 260℃ for 3h. The specific capacitance and adhesive force of the composite films are 569F/g and 22.4MPa, respectively. The internal resistance of the composite films is only 0.42Ω and its specific capacitance keep 97.6% of initial capacitance after over 1000 charge-discharge cycles.

Adopting the micro-reactor technology, CdSe quantum dots were controlled synthesized in a low toxicity system of octadecene (ODE) and oleic acid (OA) as the non-coordination solvent and the ligand, respectively. The effect of reaction conditions on particle size and the particle number of prepared CdSe quantum dots were studied in detail. The results indicated that reaction temperature has little effect on the particle number, however, appropriate high temperature favored a tight size distribution with enhanced florescence intensity. Under constant conditions, excessive Se was beneficial to generate a large number of small particles. With n(Cd):n(Se) = 1:5, the yield of CdSe quantum dots is close to 100%. The ligands quantity in the reactants directly affects concentration of the monomer. By controlling the concentration of the ligand OA and reaction time, a series CdSe quantum dots are successfully prepared displaying from blue to red fluorescence with particle size of 2.2-4.3nm.

A series of Er³⁺-doped chalcogenide glasses based on Ge-Ga-S-CsI system were prepared by melt-quenching technique with distillation processing. Properties including refractive index, infrared transmission spectra, 2.85um mid-infrared emission spectra and fluorescence lifetime under 800 nm laser excitation were measured. The infrared absorption coefficients of OH^- groups at 3um according to the infrared transmission spectra were calculated, and the constant KOH-Er, determined by the strength of interactions between Er³⁺ ions and OH^- groups in the case of energy transfer was also calculated. The effect of hydroxyl content on mid-infrared emission properties of glass samples was discussed. The results show that the remnants OH^- content of glass samples can be effectively reduced by the distillation processing. The 2.85um mid-infrared fluorescence emission intensity and fluorescence lifetime of Er³⁺ ions are also enhanced. The calculated constant KOH-Er is about 1.08×10^-16cm⁴/s. Because of the efficiency of energy transfer between Er³⁺ ions and OH^- groups, the remnants of a small amount of OH^- groups can still directly affect the intensity of 2.85um fluorescence.

Directionally solidified Al₂O₃/Er₃Al₅O₁₂(EAG) eutectic ceramic was prepared by laser zone remelting technique. The eutectic morphology and microstructure evolution investigated as a function of laser scanning rate. Moreover, the mechanical properties and toughening mechanisms were studied. The Al₂O₃/EAG eutectic ceramic consists of only two continuous phases of Al₂O₃ and EAG which interpenetrates with each other to form well-distributed three-dimensional network. The eutectic spacing is only around 0.2-2.1μm and reduces with the increase of scanning rate. At low scanning rate, the typical lamellar irregular eutectic structure is obtained. When the scanning rate reaches 800μm/s, the cellular or dendrite microstructure appears. The hardness and the fracture toughness at room temperature are measured to be 18.7GPa and 2.45MPa·m^1/2, respectively. The refined microstructure, crack deflection at phase interface and crack branching contribute to the improved toughness.

Surface modified carbon/carbon (C/C) composites were joined to Li₂CO₃-Al₂O₃-SiO₂ (LAS) glass ceramic by hot pressing bonding using MgO-Al₂O₃-SiO₂ (MAS) glass with different thicknesses as the joining material. The effect of interlayer thickness on the joint strength was discussed. Microstructures and morphologies of the as-received joints and fractured surfaces were characterized by scanning electron microscope. The results indicated that the LAS glass was directly joined to the surface modified C/C composites at 1200℃, and the room-temperature shear strength of the joints was only 10MPa, due to its poor wettability with base material. When the MAS glass was applied as interlayer, the joint shear strength increased at first and then decreased with the increase of the interlayer thickness. The maximum value of the shear strength reached 26.61MPa when interlayer thickness was 80μm.

The 2D C/C-ZrC-SiC composites were prepared through precursor infiltration and pyrolysis (PIP) process using a hybrid precursor contained polycarbosilane and organic zirconium-contained polymeric precursor. The microstructures and ablation behaviors of the prepared composites were studied. The composition and microstructure of the ablated samples were characterized by XRD and SEM, respectively. The results show that the mass ablation rate and linear ablation rate of the composites generally firstly decrease and then increase with the increasing of ZrC contents. The sample with 17.45vol% ZrC has optimum anti-ablation property. After ablation at 2200℃ for 300s via the plasma torch heating technique, the mass loss and linear recession rate is as low as 1.77mg/s and 0.55μm/s, respectively. It is found that during ultra-high temperature stage, the matrix of ZrC and SiC are oxidized into ZrO₂ and SiO₂, which form a kind of viscous binary glassy mixture. The mixture could effectively cover the ablation surface and therefore promote its anti-ablation property.

Porous carbons used for electric double layer capacitors (EDLCs) were prepared by chemical blending of phenolic resin (PF) and adipic diacid (DA). Chemical reaction of PF with diacid is manifested by a shift of carbonyl stretching peak of diacid to a higher frequency in FT-IR spectra and a higher decomposition temperature of diacid in TG curves. The influences of the ratio of w(DA) to w(PF) on pore structure, adsorption behavior and capacity performance were investigated. The specific surface area and total pore volume increase with the ratio of w(DA) to w(PF) at first and then decrease, reach the maximum at the value of w(PF)/w(DA), which are 550 cm²/g and 0.27 cm³/g, respectively. When the porous carbon used for the electrodes of electrochemical double layer capacitor (EDLC), a satisfied speci-c capacitances of 145 F/g in 30 wt% KOH aqueous electrolytes is acquired and the capacitance maintenance achieve 70% while the current density enlarged 50 times.

Carbon nano-tubes (CNTs)/hydroxyapatite (HAP) biocomposites reinforced by lithium nibate (LiNbO3) were successfully prepared by hot pressing at low temperature. The phase composition and microstructure of the composites were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM) and Energy dispersive X-ray spectroscope (EDS). Based on in-depth analysis of mechanical properties, the toughening mechanism was discussed in detail. The results indicate that LiNbO₃ addition has a great influence on mechanical properties and microstructure of the CNTs/HAp composites. The composites can be prepared at low temperature by the incorporation of LiNbO₃, and LiNbO₃ partially reacts with HAp to form CaNb₂O₆. With the rise of sintering temperature, the strength and density are improved obviously. Especially, the composite with addition of 48.5wt% LiNbO₃ hot pressed at 900℃ shows excellent flexural strength and fracture toughness, of about 135 MPa and 1.71 MPa^.m^1/2, respectively. In comparison with CNTs/HAp composite, the flexural strength and fracture toughness are increased 55% and 109%, respectively. Piezoelectric energy dissipation toughening and the improvement of density are the main contributions to the increase in the mechanical properties. These new composites may be promising bone substitute materials.

Biomimetic scaffold for bone tissue engineering was prepared by mixing Sol-Gel bioactive glass with type I collagen through freeze-drying technique. In vitro, the biocompatibility of the scaffold was investigated by observing the adhesive, proliferative and differential behaviors of the rat mesenchymal stem cells (rMSCs). In vivo, the composite scaffold seeded with osteoblasts was implanted subcutaneously into the immunodeficient mice for 6w. It was proved that the composite scaffold was non-cytotoxic and suitable for cells’ proliferation, which was confirmed by the increase of double stranded DNA (ds DNA). The differentiation of rMSCs on the composite scaffold was also observed by positive expressions of alkaline phosphatase (ALP) and osteocalcin after osteoinduction for 14d. The results of general and histological observation showed that cells successfully spread on the surface and migrated into the interior of the scaffold. Moreover, bone formation analysis of cell-scaffold constructs in vivo showed that bone tissue and blood vessels were regenerated both inside and on the border of the scaffold-stack. All results demonstrate the Sol-Gel bioactive glass-type I collagen scaffold with good biocompatibility and osteogenesis is a new ideal scaffold for bone tissue repair and regeneration.

Mg-Al hydrotalcite (MAH) with high crystallinity was prepared using urea method. The “memory effect” and the chromium(VI) adsorption property of Mg-Al Hydrotalcites were studied. The MAH, reconstructed MAH (RMAH), calcined MAH (MAO) and calcined RMAH (RMAO) were characterized by XRD, FT-IR, SEM and DSC as well as self-deconvolution analyses. The results showed that the MAH and RMAH possessed a layered structure of hydrotalcites with high crystallinity, and there was little difference in crystal structures and charge density of brucite-like sheets between MAH and RMAH. The brucite-like sheets were still held in MAO, and a little remained in RMAO with more MgAl₂O₄. The adsorbility of Mg-A1 LDOs(MAO and RMAO) to Cr(VI) anions was substantially higher than that of Mg-A1 LDHs(MAH and RMAH), mainly because of the structure “memory effect” of hydrotalcites. The adsorbility of the MAO was higher than that of the RMAO. The adsorbility decrease of the RMAO might be due to the increase of the content of spinel MgAl₂O₄ phase and the decline of brucite-like sheets in RMAO that resulted in the descent of the “memory effect” reconstruction property. This newly discovery for anionic clays is useful for the decontamination of waste waters. The Mg-Al hydrotalcite can be considered as a potential material for sorption of anions in wastewater treatment systems.

Nitrogen-doped carbon (CN_x) nanotbues were synthesized by detonation-assisted chemical vapor deposition with carbon nanotubes (CNTs) as catalysts and melamine as carbon/nitrogen sources. CNTs exhibit high catalytic activity for the metal-catalyst-free synthesis of CNx nanotubes. TEM, EDS, Mapping, XPS, Raman and TG were performed to characterize the synthesized CNx nanotubes. CN_x nanotubes exhibit compartmentalized bamboo-like structure, and contain high concentration of nitrogen (ca. 17at%), which is homogeneously distributed within compartment layers and tube walls. The pyridine-like and graphitic N are incorporated into the graphitic network. The nitrogen doping induces the decrease of the graphitization degree and results in lower oxidation-resistance temperature. The synthesis of CNx nanotubes without metal catalysts will facilitate the applications of CN_x nanotubes.

Hollow silica spheres were synthesized by template/Sol-Gel approach, using cationic polystyrene (PS) as template and tetraethoxysilane (TEOS) as precursor. The void size of hollow silica sphere was decided by the diameter of their PS templates. Hollow silica spheres with controllable size between 0.71 μm and 1.8 μm were obtained by varying the parameters of polymerization (the monomer, the initiator, the stabilizer and the polarity of the dispersion medium). The shell thickness of hollow silica spheres could be easily changed in the range of 20 nm to 60 nm by changing the TEOS concentration from 0.4 mmol/L to 0.8 mmol/L. Both the size and shell thickness of hollow silica spheres have effects on their bulk density, the thermal conductivity and strength of materials.

KNbO₃ powders with different phases and morphologies were successfully synthesized through the reaction between KOH and Nb₂O₅ by microwave-assisted hydrothermal method at 200℃. Pure KNbO₃ crystals were obtained when the concentration of KOH was maintained from 10mol/L to 14mol/L. According to the XRD, FESEM and TEM characterizations, it could be observed that as increasing the concentration of KOH from 10mol/L to 15mol/L, the KNbO₃ phases changed from rhombohedral to orthorhombic then to tetragonal, and the corresponding morphology of the KNbO₃ powders changed from pyramid-like to rod-like then to cubic-like. Some Nb₂O₅ phases were found when the concentration of KOH increased to 15mol/L. KNbO₃ ceramics were sintered from the KNbO₃ powders by conventional processing. The piezoeletric properties such as the piezoeletric constant d₃₃, the relative permittivity ε₃₃/ε₀, the dielectric loss tanδ, the electromechanical coupling factors kp and the mechanical quality factor Q_m of the sintered KNbO₃ ceramics were 80 pC/N, 302, 0.023, 0.17, 70, respectively. The tetragonal to orthorhombic and cubic to tetragonal phase transitions temperatures were 223℃ and 420℃, respectively.