Novel and efficient system of a visible-light-responsive organic photoelectrocatalyst working in a water phase
Novel and efficient system of a visible-light-responsive organic photoelectrocatalyst working in a water phase
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DOI：
10.1002/cphc.200301060
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发表时间：
2004-05-17
期刊：
影响因子：
2.9
通讯作者：
Norimatsu, T
中科院分区：
文献类型：
--
作者：
Abe, T;Nagai, K;Norimatsu, T
采用气相沉积法在indiumątin氧化（ITO）板上制备了PV/H2Pc光电极器件，该器件由涂覆在ITO上的PV和涂覆在PV上的H2Pc组成（ITO/PV/H2Pc）。光电化学测量过程如图1 b所示。本研究的重点是详细了解双分子层在水相中的光电化学特性，并以易分解的2-巯基乙醇（ME）[7]作为给电子试剂。图2显示了ITO/PV/H2Pc在照明（a和b）和黑暗(c)下的典型循环伏安图（CV）。在测量有ME和没有ME的cv时（分别见图2中的a）和b)，在有ME和没有ME的cv中，μA cmĀ2量级的光阳极电流明显大于Ā0。10 V（相对于Ag/AgCl）。在黑暗中的对照实验中（图2中的c），即使在ME存在的情况下，也无法观察到阳极电流。图2a清楚地表明，发生在H2Pc/水界面的高效光电流产生与ME给电子到电极的耦合，因此不同于在Schottky结的p型semiconductorąliquid界面上的普通光电极特性。此外，通过考虑MEC/MEĀ偶对的形式电位（%+ 0.6 V vs. Ag/AgCl），[8]，表明涉及硫醇氧化的光电流可分配给光电催化电流。在ITO/PV/H2Pc上产生的光电流来源的细节将在后面讨论。图3a显示了ITO/PV/H2Pc的典型电流变化，这是通过打开和关闭illumina-引起的
The photoelectrode device of PV/H2Pc was prepared by vapor deposition on an indiumątin oxide (ITO) plate, and consisted of PV coated on the ITO and H2Pc coated on top of the PV (ITO/PV/H2Pc). The procedure of photoelectrochemical measurement can be seen in the schematic illustration (Figure 1 b). The present study was focused on the detailed understanding of photoelectrochemical characteristics of the bilayer in the water phase, so that an easily decomposed substance, 2-mercaptoethanol (ME),[7] was used as an electron-donating reagent. Figure 2 shows a typical cyclic voltammogram (CV) at ITO/PV/H2Pc under both illumination (a and b)) and dark (c). When measuring the CVs with and without ME (a) and b) in Figure 2, respectively), in the former a large photoanodic current of μA cmĀ2 order noticeably appeared at more positive potential than Ā0. 10 V (vs. Ag/AgCl). In a control experiment in the dark (c) in Figure 2), no anodic current can be observed, even in the presence of the ME. Figure 2a evidently exhibits that the efficient photocurrent generation taking place at the H2Pc/water interface is coupled with the electron donation from the ME into the electrode, and thereby differs from an ordinary photoelectrode characteristic at a p-type semiconductorąliquid interface of the Schottky junction. In addition, by considering the formal potential of MEC/MEĀ couple (%+ 0.6 V vs. Ag/AgCl),[8] it appears that the photocurrent involving the thiol oxidation is assignable to the photoelectrocatalytic current. The details for the origin of the photocurrent generated at the ITO/PV/H2Pc will be discussed later. Figure3a shows a typical current change of the ITO/PV/H2Pc, which is induced by switching on and off the illumina-