涂敷氧化铁电极的光电化学和介电性质的研究

本文利用涂敷Fe(C_8H_(15)O_2)_3[2-乙基己醇酸铁(Ⅲ)]于Fe,Ti,Pt金属基片上,热氧化分解制成多晶氧化铁电极。对其介电、光电化学行为的测定,表明它们与利用热氧化法以及阳极氧化法所制成的多晶氧化铁电极的性能相似,具有n型半导体的特性。借助于交流阻抗的快速测定,并且选择了一种等效电路,测定了空间电荷区电阻、电容的变化。这种方法可以用来监测光电极的相对光效率。     

电解池电阻和容抗的快速测定仪

利用锁定放大器, 恒电势仪, 压控频率正弦波信号发生器等组装成电解池电阻和容抗的快速测定仪。可以快速地自动测是和绘出阻抗谱图和电阻/容抗～时间图。采用微小恒定振幅正弛交流电流(<10 μA)作为微扰, 数据可能较为可靠。给出了线路及所需滤波器元件的数据, 说明仪器各部份之间的干扰可以减少。测定了滴汞电极在1 mol L~(-1)Na_2SO_4溶液中及1 mol L~(-1)Na_2SO_4被正庚醇饱和的溶液中的微分电容～电势数值。证明仪器工作良好。另外, 从实验数据和理论分析, 均表明D.C.Grahame的被广泛引用的有关经典数据有误。本文做了修正。还测定了半导体氧化铁电极在光照下黑暗中的阻抗谱图和氧化银电极充电和停止充电后开路下的电阻～时间图, 显示了仪器在电化学研究中利用的可能性。     

PHOTOELECTROCHEMICAL AND DIELECTRIC PROPERTIES OF PAINTED IRON OXIDE ELECTRODES

Polycrystalline iron oxide electrodes made by thermal decomposition of Fe (C_8H_(15)O_2)_3[Iron (Ⅲ) 2-ethylhexanoate] on Fe, Ti and Pt substrates were characterized with respectto their dielectric and photoelectrochemical properties. The thermal decomposition process pro-duces a stable ferric oxide lattice (Fe_2O_3) possessing n-type semiconductor characteristics. Thephotoelectrochemical behavior of painted electrodes was shown to be equivalent to iron oxideproduced by thermal or anodic oxidation. From A. C. impedance measurements, an equivalentcircuit of the interface was constructed, that provided values for the space charge capacitanceand resistance. With the equivalent circuit, impedance measurements can be used to ascertainrapidly the relative photo-efficiencies of photoanodes.