Unexpected phenomena displayed by low boron-doped diamond (BDD) electrodes are disclosed in the present work. Generally, the presence of sp2 non-diamond carbon impurities in BDD electrodes causes undesirable electrochemical properties, such as a reduced potential window and increased background current etc. However, we found that the poten-tial window and redox reaction in normally doped (1%) BDD and low doped (0.1%) BDD exhibited opposite tendencies depending on the extent of sp2 carbon. Moreover, we found that contrary to the usual expectations, low-doped BDD con-taining sp2 carbon hinders electron transfer, whereas in line with expectations, normally-doped BDD containing sp2 exhibits enhanced electron transfer. Surface analysis by X-ray/ultraviolet photoelectron spectroscopy (XPS/UPS) and electro-chemical methods are utilized to explain these unusual phenomena. This work indicates that, the electrochemical proper-ties of low-doped BDD containing sp2 might be due partially to the high level of surface oxygen, the large work function, the low carrier density and the existence of different types of sp2 carbon.

中文翻译：

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含 sp2 碳的低掺杂硼掺杂金刚石电极的异常电化学性能

本工作公开了低掺硼金刚石 (BDD) 电极显示的意外现象。通常，BDD 电极中 sp2 非金刚石碳杂质的存在会导致不良的电化学性能，例如降低电位窗口和增加背景电流等。 然而，我们发现在正常掺杂 (1%) 中的电位窗口和氧化还原反应) BDD 和低掺杂 (0.1%) BDD 表现出相反的趋势，具体取决于 sp2 碳的程度。此外，我们发现与通常的预期相反，含有 sp2 碳的低掺杂 BDD 会阻碍电子转移，而与预期一致的是，含有 sp2 的正常掺杂 BDD 表现出增强的电子转移。X 射线/紫外光电子能谱 (XPS/UPS) 和电化学方法的表面分析被用来解释这些不寻常的现象。这项工作表明，含sp2的低掺杂BDD的电化学性质可能部分是由于表面氧含量高、功函数大、载流子密度低以及存在不同类型的sp2碳。