Synthesis and Characterization of W-doped TiO_2 Supported by Hybrid Carbon Nanomaterials of Multi-walled Carbon Nanotubes and C_(60) Fullerene by a Hydrothermal Method

W-doped TiO2 supported by hybrid carbon nanomaterials of multi-walled carbon nanotubes and C60 fullerene was synthesized by a simple hydrothermal method. The material displayed high visible light photocatalytic activity. X-ray diffraction, field emission transmission electron microscopy, ultra violet/visible light absorption and photoluminescence spectroscopy were used to characterize the material as photoeatalyst. Photocatalytic activity on the degradation of Rhodamine B dye in an aqueous solution under ultraviolet light and visible light irradiation was also studied. The experimental results indicated that the photocatalytic activity of the material was much higher than that of pure TiO2 or Degussa P25 TiO2.

Effects of C60 on the Glass Transition Temperature of Carbazole-based Photorefractive Polyphosphazenes

The bi-functional carbazole-based photorefractive polyphosphazenes with different content of C_（60）-doped were fabricated. The glass transition temperature（T_g） of these polymer composite materials was determined using a differential scanning calorimetric（DSC） method. According to the DSC measurement results with different heating rates, the variation of T_g and the active energy of glass transition（E_g） were analyzed in detail. The analysis results indicate that the transition region shifts to higher temperatures with increasing heating rate, and C_（60） content（below 1.0 wt%） can influence the T_g of photorefractive polyphosphazenes. The T_g first increases and then decreases with the C_（60） content（below 1.0 wt%）. The probable causes of the influence of C_（60） on T_g was proposed.

In situ electrical resistance and activation energy of solid C_(60) under high pressure

The in situ electrical resistance and transport activation energies of solid C60 fullerene have been measured under high pressure up to 25 GPa in the temperature range of 300-423 K by using a designed diamond anvil cell. In the experiment, four parts of boron-doped diamond films fabricated on one anvil were used as electrical measurement probes and a W-Ta thin film thermocouple which was integrated on the other diamond anvil was used to measure the temperature. The current results indicate that the measured high-pressure resistances are bigger than those reported before at the same pressure and there is no pressure-independent resistance increase before 8 GPa. From the temperature dependence of the resistivity, the C60 behaviors as a semiconductor and the activation energies of the cubic C60 fullerene are 0,49, 0.43, and 0.36 eV at 13, 15, and 19 GPa, respectively.

Regulation of Glucose Oxidase Activity through Interaction with Fullerene Derivatives

The 2-（hydroxymethyl）pyridine modified C60 （PY-C60） and methoxydiglycol modified C60 （MDG-C60） are synthesized using Bingel-Hirsch reaction and characterized by nuclear magnetic resonance （NMR） and mass spectra. PY-C60 and MDG-C60 can bind to glucose oxidase （GOx） and quench the fluorescence of tryptophan （Trp） residue in GOx through static mechanism. The conformation of GOx is disturbed after formation of complex with these fullerene derivatives. Kinetic analysis indicates that PY-C60 and MDG-C60 may affect the catalytic activity of GOx with a partial mixed-type inhibition mechanism. In the plasma glucose concentration range （3.6--5.2 mmol·L-1）, PY-C60 may significantly accelerate the catalytic velocity of GOx, however, MDG-C60 exerts almost no obvious change to the initial velocity of GOx, suggesting that elaborate design of molecular structure of fullerene derivative is very important for regulating the biological activity of fullerene-enzyme complex.

Transient Absorption Spectral Characterization of Electron Transfer between Fullerenes (C_(60)/C_(70)) and N,N,N′,N′-Tetra(p-methylphenyl)-4,4′-diamino-1,1′-diphenyl Sulphide (TPDAS)

In search of new systems with a photoexcited redox pair which exhibits a strong and stable photoinduced absorption band to understand the photophyscial and photochemical properties of electron transfer between fullerenes (C 60/C 70) and organic donor [N,N,N′,N′-tetra(p-methylphenyl)-4,4′-diamino-1,1′-diphenyl sulphide (TPDAS)], we studied characteristic absorption spectra in the near-IR region obtained from 532 nm nanosecond laser flash photolysis of a mixture of the fullerenes (C 60/C 70) and TPDAS in polar solvents. When fullerenes (C 60/C 70) were photoexcited, the rise of the radical anion of fullerenes (C 60/C 70) with the rapid decay of their excited triplet states were observed in benzonitrile. It can be deduced that the electron transfer reaction does take place from TPDAS to excited triplet state of fullerenes (C 60/C 70). The rate constants (k et) and quantum yields (Φ et) of this process have been also evaluated.

Photoinduced Electron Transfer between N,N,N′,N′-Tetra-(p-methylphenyl)-4,4-diamino-1,1′-diphenyl Ether (TPDAE) and Fullerenes (C_(60)/C_(70)) by Laser Flash Photolysis

The photoinduced electron-transfer reaction of N,N,N′,N′-tetra-(p-methylphenyl)-4,4′-diamino-1,1′-diphenyl ether (TPDAE) and fullerenes (C 60/C 70) by nanosecond laser flash photolysis occurred in benzonitrile. Transient absorption spectral measurements were carried out during 532 nm laser flash photolysis of a mixture of the fullerenes (C 60/C 70) and TPDAE. The electron transfer from the TPDAE to excited triplet state of the fullerenes (C 60/C 70) quantum yields and rate constants of electron transfer from TPDAE to excited triplet state of fullerenes (C 60/C 70) in benzonitrile have been evaluated by observing the transient absorption bands in the near-IR region where the excited triplet state, radical anion of fullerenes (C 60/C 70) and radical cations of TPDAE are expected to appear.