共查询到18条相似文献,搜索用时 62 毫秒
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鲁米诺在铂电极上阳极电致化学发光的机理研究 总被引:1,自引:0,他引:1
研究了碱性鲁米诺溶液在多晶铂电极上的阳极电致化学发光(ECL)行为,观察到电极的预极化处理和溶解氧跟发光峰强度和峰形有直接关系。结合XPS谱图和Pt,Pt|S~a~d~s修饰电极的循环伏安特性,给出了鲁米诺阳极ECL两个发光通道的可能反应机理:(1)鲁米诺阴离子在表面有新鲜Pt原子的电极上氧化生成鲁米诺自由基,然后迅速与溶液中的氧反应形成0.22V(vs.Ag)处的发光肩峰;(2)电极表面的铂氧化物能加速原子态氧的发生过程,并增大0.60V(vs.Ag)附近ECL主峰的发光强度。 相似文献
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钴电极在碱性溶液中氧化还原反应的现场共聚焦显微喇曼光 … 总被引:1,自引:0,他引:1
采用现场共聚焦显微喇曼光谱研究钴电极在碱性溶液中的氧化还原行为和生成物的喇曼光谱特征。研究结果表明:电位正向扫描时,在-0.64V左右Co氧化生成Co(OH)2和CoO,随着电位正移逐步生成Co3O4,在正电位区电极表面层主要是Co3O4,CoOOH和CoO2等;电位负向扫描时,电极由的高价含氧化合物相继还原为Co3O4和Co(OH)2,并最终还原为Co。由不同电位下的生成物的喇曼光谱可以看出;电 相似文献
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氯化物熔体中钬离子在铁电极上的电还原 总被引:3,自引:0,他引:3
用循环伏安,恒电位断电,电位阶跃,X射线衍射和电子探针研究了Ho(Ⅲ)在氯化物熔体中铁电极上还原的电极过程及表面合金层的物相.Ho(Ⅲ)在铁电极上还原,首先形成多种钬和铁的金属间化合物,然后才析出金属钬,电荷转移是可逆的,测定了Ho-Fe体系四个金属间化合物的生成自由能,Ho在合金化阴极中的扩散系数及扩散活化能。 相似文献
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本文制备了嵌于多孔阳极氧化铝(AAO)膜中直径为200 nm,间距为450 nm的高密度(5.7 × 108 cm-2)的金纳米电极阵列,纳米电极分布规则,尺寸高度均一。我们将该金纳米电极阵列作为双极电极阵列,可将电极一侧的电化学法拉第信号在另一侧电极上转化成电致化学发光(ECL)信号,从而实现对单个铂纳米颗粒上氢气析出反应(HER)进行亚微米空间分辨率的电化学成像。本文介绍的方法为高空间分辨率成像电催化材料、能源材料以及细胞过程的局部电化学活性提供了一个良好的平台。 相似文献
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研究发现罗丹明B在碱性溶液中铂电极上有较强的电致化学发光行为.通过对不同NaOH浓度,以及对不同支持电解质的考察,确定最佳电致化学发光条件.在最优条件下,在1.2×10-7~1.1×10-6mol/L浓度范围内,罗丹明B的电致化学发光强度与其浓度成线性关系,最低检测限为9.0×10-8mol/L(S/N=3).将罗丹明B同一些生物活性物质相配合,然后通过罗丹明B的ECL技术对生物活性物质进行检测. 相似文献
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运用电化学循环伏安和石英晶体微天平研究了1,4-丁二醇(1,4-BDL)在Pt电极及以Sb和S吸附原子修饰的Pt(Pt/Sbad和Pt/Sad)电极上的吸附和氧化过程.结果表明,1,4-丁二醇的氧化与电极表面氧物种有着极其密切的关系,表面质量变化提供了吸附原子电催化作用的新数据.Pt电极表面Sb吸附原子能在较低的电位下吸附氧,可显提高1,4-丁二醇电催化氧化活性.与Pt电极相比,1,4-丁二醇在饱和吸附Sb原子的Pt电极上氧化的峰电位负移了0.20V,峰电流增加了1.5倍.相反,Pt电极表面S吸附原子的氧化会消耗表面氧物种,饱和吸附的S原子抑制了1,4-丁二醇的氧化. 相似文献
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The co-catalytic effect of W on the oxidation of CO and methanol is investigated by using differential electrochemical mass spectrometry (DEMS). DEMS reveals that CO oxidation starts at 120 mV, overlapping with W oxidation. The action of W consists in shifting the pre-peak from 450 mV (as observed on pure Pt) to 200 mV. In this shifted pre-peak only 2% of the total adsorbed CO is oxidized independently from the W coverage, as compared to 10% on pure Pt. A correlation between the surface coverage of W as determined by XPS with the W oxidation peak charge in cyclic voltammetry suggests that the oxidation is a six-electron process.Dedicated to Prof. Wolf Vielstich on the occasion of his 80th birthday in recognition of his numerous contributions to interfacial electrochemistry. 相似文献
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Pt/钇稳定氧化锆固体电解质在高温下的电化学性质 总被引:1,自引:0,他引:1
用交流阻抗技术研究了二电极、三电极Pt/钇稳定氧化锆(简称YSZ)高温固体电化学体系.开路电位下,Pt/YSZ体系只有一个阻抗半圆,对应于电极体系的电化学活化控制过程,极化电阻随温度变化的表观活化能为171.5kJ/mol.Pt/YSZ界面的双电层电容约为300μF/cm2.阳极极化下,交流阻抗极化电阻显著减小;阴极极化下,极化电阻反而增大,并出现浓差控制现象. 相似文献
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Surface processes of CO2 reduction on Pt(210), Pt(310), and Pt(510) electrodes were studied by cyclic voltammetry. Different surface structures of these platinum single crystal electrodes were obtained by various treatment conditions. The experimental results illustrated that the electrocatalytic activity of Pt single crystal electrodes towards CO2 reduction is decreased in an order of Pt(210)>Pt(310)>Pt(510), i.e., with the decrease of (110) step density on well-defined surfaces. When the surfaces were reconstructed due to oxygen adsorption, the catalytic activity of all the three electrodes has been enhanced to a cer- tain extent. Although the activity order remains unchanged, the electrocatalytic activity has been en- hanced more significantly as the density of (110) step sites is more intensive on the Pt single crystal surface. It has revealed that the more open the surface structure is, the more active the Pt single crystal electrode will be, and the easier for the electrode to be transformed into a surface structure that exhib- its higher activity under external inductions. However, the relatively ordered surfaces of Pt single crystal electrode are comparatively stable under the same external inductions. The present study has gained knowledge on the interaction between CO2 and Pt single crystal electrode surfaces at a micro- scopic level, and thrown new insight into understanding the surface processes of electrocatalytic re- duction of CO2. 相似文献
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Surface processes of CO2 reduction on Pt(210), Pt(310), and Pt(510) electrodes were studied by cyclic voltammetry. Different surface structures of these platinum single crystal electrodes were obtained by various treatment conditions. The experimental results illustrated that the electrocatalytic activity of Pt single crystal electrodes towards CO2 reduction is decreased in an order of Pt(210)>Pt(310)>Pt(510), i.e., with the decrease of (110) step density on well-defined surfaces. When the surfaces were reconstructed due to oxygen adsorption, the catalytic activity of all the three electrodes has been enhanced to a certain extent. Although the activity order remains unchanged, the electrocatalytic activity has been enhanced more significantly as the density of (110) step sites is more intensive on the Pt single crystal surface. It has revealed that the more open the surface structure is, the more active the Pt single crystal electrode will be, and the easier for the electrode to be transformed into a surface structure that exhibits higher activity under external inductions. However, the relatively ordered surfaces of Pt single crystal electrode are comparatively stable under the same external inductions. The present study has gained knowledge on the interaction between CO2 and Pt single crystal electrode surfaces at a microscopic level, and thrown new insight into understanding the surface processes of electrocatalytic reduction of CO2. 相似文献
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Steady-state polarization curves are compared in solutions of 0.5 M H2SO4 + O2 (saturated), 0.5 M H2SO4 + (0.005–0.1) M CH3OH, and 0.5 M H2SO4 + (0.005–0.1) M CH3OH + O2 (saturated) on a Pt/Pt electrode. A considerable difference is found between the currents in mixed solutions and those expected based on the principle of additivity of currents in CH3OH and O2 individual solutions. The surface coverages with the CH3OH and O2 adsorption products are determined in the potential range of 0.2–0.9 V (RHE). Open-circuit potentials are measured in mixed solutions. The obtained results suggest that the direct heterogeneous interaction between methanol and oxygen occurs alongside with faradaic reactions. This is assumed to lead to a decrease in methanol electrooxidation currents at E ≥ 0.8 V and their increase at E ≤ 0.65 V. 相似文献
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As a representation of metalloproteins, metallothionein (MT), which plays important biological and environmental roles such as in the metabolism and detoxification of some metals, was detected at bismuth film electrode (BiFE) by differential pulse anodic stripping voltammetry (DPASV). In pH 2–5.5, two well-defined anodic peaks were produced and attributed to the Zn2+ and Cd2+ inherent to MT. The calibration plot of DPASV peak currents for Cd2+ inherent to MT versus MT concentrations showed a good linearity with a detection limit of 3.86 × 10−8 mol/L for MT. As a non-toxic excellent electrode material, BiFE shows good performance for detecting MT, and is expected to find further applications in the studies of many other metalloproteins. 相似文献