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181.
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The degradation and decolourization of direct dye (Everdirect supra turguoise blue, FBL), acidic dye (Isolan orange S-RL) and vat dye (Indanthren red FBB) have been investigated by solar/TiO2 process. The effects of solution pH, dye concentration, dosage of TiO2 and nano-size of TiO2 have been studied. The increase in initial pH (3, 5 and 11) and dye concentration decrease the removal rate. The treatment for FBB and FBL dye solutions is more efficient than that of S-RL.Under optimum conditions, the color removal is found to be almost complete for FBB and FBL while that of S-RL also reaches 95%. Langmuir adsorption isotherm and modified Langmuir-Hinshelwood kinetic model (L-H model) have been fitted to the experimental data and found to correlate the adsorption patterns as well as the kinetics of the dyes studied. 相似文献
183.
This work provides kinetic and transport parameters of Li-ion during its extraction/insertion into thin film LiNi0.5Mn1.5O4 free of binder and conductive additive. Thin films of LiNi0.5Mn1.5O4 (0.2 μm thick) were prepared on electronically conductive gold substrate utilizing the electrostatic spray deposition technique. High purity LiNi0.5Mn1.5O4 thin film electrodes were observed with cyclic voltammetry, to exhibit very sharp peaks, high reversibility, and absence of the 4 V signal related to the Mn3+/Mn4+ redox couple. The electrode subjected to 100 CV cycles of charge/discharge delivered a capacity of 155 mAh g−1 on the first cycle and sustained a good cycling behavior while retaining 91% of the initial capacity after 50 cycles. Kinetics and mass-transport of Li-ion extraction at LiNi0.5Mn1.5O4 thin film electrode were investigated by means of electrochemical impedance spectroscopy. The apparent chemical diffusion coefficient (Dapp) value determined from EIS measurements changed depending on the electrode potential in the range of 10−10-10−12 cm2 s−1. The Dapp profile shows two minimums at the potential values close to the peak potentials of the corresponding cyclic voltammogram. 相似文献
184.
Anodic dissolution of Au is facilitated by the presence of thiourea owing to formation of strongly complexed Au ions. The present paper reports studies of this process using cyclic voltammetry (CV), chronopotentiometry and chronoamperometry, usefully complemented by nanogravimetry employing an electrochemical quartz-crystal nanobalance (EQCN). The molar masses per faraday for Au dissolution were determined from EQCN measurements, coupled with information derived from CV, chronopotentiometry and chronoamperometry, and clearly indicate that Au becomes dissolved over the potential range 0.45—0.65 V vs RHE via a 1e– oxidation process in 0.5 M HClO4 solution containing thiourea. The peak potential for Au dissolution in the presence of thiourea is about 600 mV less positive than that in the presence of Br– or Cl– (1.20 V vs RHE for Br– and 1.39 V vs RHE for Cl–). The linear relationship between anodic peak currents at about 0.630 V vs RHE and square-root of the sweep rate indicates that the Au dissolution process is diffusion-controlled. The anodic current efficiency for Au dissolution is 93%. 相似文献
185.
M.A. Montero 《Electrochimica acta》2007,52(5):2083-2090
An alternative method for the determination of the kinetic parameters involved in the elementary steps of the reaction mechanism of the hydrogen electrode reaction is proposed. It is based on the determination of the variation of the polarization resistance in a tubular platinum electrode with a laminar flow of electrolyte as a function of the activity of protons of the electrolyte solution. A theoretical expression that relates the experimental variables and the equilibrium polarization resistance is developed, which takes into account the current distribution along the electrode surface. The results are compared with others obtained previously, contributing to the verification of the kinetic mechanism through a completely different experimental procedure. 相似文献
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Spherical lithium manganese oxide spinel was synthesized by an ultrasonic spray pyrolysis method, and has been characterized using X-ray diffraction, scanning electron microscopy, transimission electron microscopy and electrochemical cycling at 3 V regions. The LiMn2O4 powders were composed of about 10 nm-sized primary particles. The delivered discharge capacity of the synthesized nano-material was 125 mAh g−1 between 2.4 and 3.5 V and its retention was about 96% upon 50 cycling. From the high resolution transmission electron microscopic study, it was found that structural transition of the parent material did not occur even after the 50th electrochemical cycling on the 3 V region. It seems that the reversible structural change is possible for nanocrystalline LiMn2O4 as observed by the X-ray diffraction and transition electron microscopic observations. 相似文献
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研究了一种能粘多种材质的溶剂型鞋用大底胶。该胶为一种聚氨酯改性氯丁、SBS接枝胶,粘接范围广,对PU、TPR、SBS等材质粘接性能比氯丁接枝胶好,适合鞋厂流水生产线;所用溶剂毒性相当低,对人无害,有利于劳动保护和环境保护。 相似文献