Abstract

The relationship between the morphology of the photo-electrode of copper bismuth oxide (CuBi₂O₄) and the activity to generate cathodic photo-current in a deoxygenated aqueous electrolyte was investigated. The electrodes were fabricated by the electrodeposition of the precursor on a conductive substrate following heat treatment. As a simple comparison, a randomly porous electrode was compared with a dense electrode. A dense electrode and a porous electrode were fabricated by selecting the potential to deposit the precursor; formation of the electrode was confirmed by measuring X-ray diffraction patterns and scanning electron microscope images. The values of the absorbed photon to current efficiency were calculated by measuring steady photocurrents in a deoxygenated electrolyte at a constant potential under irradiation of monochromatic visible lights. The dense electrode shows larger values than the porous electrode. To consider the difference in the values between the electrodes, the values were also calculated for the current generated in the electrolyte of dissolved oxygen to scavenge electrons. Eventually, it is considered that for CuBi₂O₄ electrodes, dense morphologies are more suitable than porous morphologies to produce hydrogen by photo-electrochemical water reduction in terms of charge separation inside the electrode.

Graphic abstract

Dense and porous photo-electrodes of copper bismuth oxide were fabricated by selecting the potential to deposit the precursor and following heat treatment. The former is more efficient to generate the current for water photo-reduction in a deoxygenated aqueous electrolyte due to more facile transfer of electrons inside the electrode.

中文翻译：

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氧化铜铋光电极的形态与减水有关的光电化学活性之间的关系

摘要

氧化铜铋（CuBi ₂ O _4）的光电极形态之间的关系），并研究了在脱氧的水性电解质中产生阴极光电流的活性。通过在热处理之后将前体电沉积在导电基板上来制造电极。作为简单的比较，将随机多孔的电极与致密的电极进行了比较。通过选择沉积前体的电位来制造致密电极和多孔电极。通过测量X射线衍射图和扫描电子显微镜图像确认电极的形成。通过在单色可见光的照射下以恒定电势测量脱氧电解质中的稳定光电流来计算吸收的光子对电流效率的值。致密电极显示出比多孔电极更大的值。为了考虑电极之间的值的差异，还计算了在溶解氧的电解质中产生的电流以清除电子的值。最终，人们认为对于CuBi_在2 O ₄电极上，致密形态比多孔形态更适合于通过光电化学减水来产生氢，从而降低电极内部的电荷。

图形摘要

通过选择沉积前体的电位并随后进行热处理，制造了氧化铜铋的致密且多孔的光电极。前者由于在电极内部更容易转移电子，因此在脱氧的水性电解质中更有效地产生用于水光还原的电流。