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导电高聚物修饰纳米尺度TiO~2多孔膜电极的光电化学研究 总被引:20,自引:1,他引:20
用光电化学方法研究了用导电高聚物修饰的纳米晶TiO~2多孔膜电极在不含氧化还原对和含不同氧化还原对体系电解质溶液中的光电转换过程。TiO~2/导电高聚物多孔膜电极为双层n型半导体结构,内层TiO~2多孔膜的禁带宽度为3.26eV,外层聚吡咯(PPy)膜的禁带宽度为2.23eV,而聚苯胺(PAn)膜的禁带宽度为2.88eV。用导电高聚物修饰半导体电极能使其在可见光区的光吸收增加,光电流增强,且起始波长红移至>600nm,使宽禁带半导体电极的光电转换效率得到明显改善。 相似文献
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本文用内禀反应坐标法讨论了甲硫醛分子的脱氢反应机理. 在4-31G基组上对此反应做了量子化学从头计算和反应路解析, 得出过渡态结构, 反应势能曲线, 活化能, 反应热以及沿反应坐标反应系的一些物理量的变化, 并对过渡态做了振动分析. 所得结果与甲醛,甲硫醇和甲醇等分子的脱氢反应结果做了对比. 还给出沿反应坐标分子间弹性碰撞阶段和最佳碰撞角等信息. 同时, 计算了反应的频率因子A,讨论了反应速率常数k值与温度的关系. 相似文献
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《Composite Interfaces》2013,20(6):609-619
The immobilization of norbornadiene (NBD) moieties onto nano-sized silica surface by the direct condensation of the surface terminal amino groups of hyperbranched poly(amido amine) (PAMAM)-grafted silica with 3-phenyl-2,5-norbornadiene-2-carboxylic acid is examined. It is found that the immobilization of NBD moieties onto the silica successfully proceeds in the presence of N,N′-dicyclohexylcarbodiimide (DCC) as a condensing agent. The immobilized NBD moieties onto the silica surface increases with increasing amount of amino groups of hyperbranched PAMAM-grafted silica, but the percentage of amino groups used for the immobilization of NBD moieties is decreased. The immobilized NBD moieties on the silica surface are readily isomerized to quadricyclane (QD) by photo-irradiation in n-hexane. Stored thermal energy by QD-immobilized silica is released as thermal energy by heating. The stored thermal energy of QD-immobilized silica increases with progress of the photo-irradiation time and became constant, about 30 J/g-silica, after 2 h. 相似文献
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Wonihl Cho Youngsoon Baek Young Chai Kim Masakazu Anpo 《Research on Chemical Intermediates》2002,28(4):343-357
The decomposition of natural gas over Pd-NiO/Al2O3 and Pt-Sn/Al2O3 is carried out in a microwave catalytic reaction at room temperature. The decomposition of methane is caused by collision by excitation of unstable electronic state. Measuring the flow rate and plasma power can provide kinetic data and indicate the mechanism. The conversion of C2 products increases from 47 to 63.7% in the microwave plasma catalytic reaction with electric field. Comparing the activities of catalysts, Pd-NiO/Al2O3 bimetallic catalyst is more active than Pt-Sn/Al2O3 catalyst because of modification of the surface of catalysts by carbon formation. The kinetic modeling of plasma of methane conversion seems related to the power of the electric discharge. It was also revealed that proper coking or polymeric carbon formation improves the catalytic activity; therefore, the conversion of methane may increase over Pd-Ni/Al2O3 catalyst in the plasma system. 相似文献
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用从头算和静电势方法研究了光电转换模拟体系C~6H~7N+C~6H~8N^+中的分子间电荷转移。通过计算分子间的静电势分布, 确定了电子在分子间运动所需穿透势垒的特性, 对电子穿透几率及穿透弛时间等参数作了理论预测并研究了外接基团的影响。在分子间距d=0.35nm时, 穿透几率P=2.94x10^-^4, 穿透弛豫时间τ=3.4x10^-^1^0s, 在此情况下, 由模型分子组成的截面积为10x1mm^2的多层分子膜, 在光照条件下可能产生的理论光电流为0.28A。 相似文献
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在胶束形成前染料分子的能量转移与预胶束基本性质的研究 总被引:7,自引:0,他引:7
本工作对罗丹明6G(1)与罗丹明-B(2)两种染料在十二烷基硫酸钠(SLS)溶液中的能量转移进行了研究。当SLS浓度远低于它的cmc值时可明显地观察到两种染料间的能量转移, 说明在此浓度下SLS的预胶束已生成。以Ia/(Id+Ia)值表示两种染料分子间能量转移的效率, 在SLS浓度增长过程中, 存在着一个效率的极大值。当溶剂水中加入不同量的DMSO时, 发现效率极大值移向SLS的高浓度处。这一结果表明:分子间的疏水作用力是SLS分子形成预胶束的推动力。 相似文献
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