V5+‐doped Ag/AgCl photocatalysts were prepared via the ion exchange method. The catalysts were characterized using X‐ray diffractometry, transmission electron microscopy, and energy‐dispersive X‐ray, X‐ray photoelectron, Fourier transform infrared and ultraviolet–visible spectroscopies. The V5+‐doped Ag/AgCl photocatalysts show much higher photocatalytic activities than Ag/AgCl under visible light irradiation for methyl orange (MO) decomposition. Especially, the 2.0 wt% V5+‐doped Ag/AgCl photocatalyst shows the highest photocatalytic activity and also high stability after five cycles. The MO degradation rate during each cycle is almost maintained at 97%. Electron spin resonance spectroscopy and radical trapping experiments reveal that holes play an important role in the photocatalytic process. 相似文献
To investigate the effects of ionic liquids (ILs) on the oxidative combustion characteristics of coal, the oxidation characteristics of ILs on coal, such as characteristic temperature, thermal mass loss rate, and oxidation kinetics characteristic parameters, were determined. The results the [BMIm][I]-treated coal samples increased cracking temperature (T1), maximum oxidization mass gain (T2), ignition temperature (T3), burnout temperature (T4), minimum thermal rate (Ta), maximum thermal energy (Tb), and maximum thermal rate (Tc) by 33.2, 29.3, 20.7, 42.8, 11.4, 23.0, and 27.9 °C, respectively. The increase mass ratio of coal samples treated with ILs increased and decreased at the water evaporation and thermal decomposition stages, respectively. The apparent activation energy (Ea) of coal samples treated with ILs increased, and the mechanism function also changed accordingly. These showed that the ILs improved the thermal stability of the coal samples in the stages of absorbing oxygen and increased mass, and the loss of combustion. The ILs caused damage to the molecular structure of the coal and ultimately effected changes in the combustion performance. In addition, the [BMIm][BF4] hardly weakens the inhibitory effectiveness of the coal sample over time; coal spontaneous combustion could be effectively inhibited.
Molecular orbital calculations of some extended sesquifulvalene compounds as On with olefins bridge and Tn with thiophenes bridge as well as their corresponding cyclopentadienyl‐iron(II) coordination compounds as IOn and ITn at the hybrid density functional theory level demonstrate that the dipole moment depends linearly on the molecular size (n), and the linear polarizability depends linearly on n2 as well as the first hyperpolarizability also has a linear dependence on n3. 相似文献
The first hyperpolarizability of two tungsten-carbonyl complexes, tungsten pentacarbonyl pyridine and tungsten pentacarbonyl trans-1,2-bis(4-pyridyl)-ethylene, has been studied by the high-level TDDFT method. The consideration of the solvent effect and intermolecular pi-pi weak interaction in the calculations quantitatively improve the final result of both the electronic excitations and the first hyperpolarizabilities. By using the orbital decomposition scheme (J. Phys. Chem. A 2006, 110, 1014-1021), the NLO mechanisms of these two complexes have been ascribed to the dominant contribution from the metal-to-ligand charge transfer, with HOMO --> LUMO character, and the indispensable contribution from the intraligand charge transfer as well. A supplementary formula has been proposed to implement the orbital-pair transition analysis. This study reports the significant influences of solvation and intermolecular interactions on the first hyperpolarizabilities of organometallic NLO chromophores. 相似文献