Unexpected phenomena displayed by low-boron-doped diamond (BDD) electrodes are disclosed in the present work. Generally, the presence of sp(2) nondiamond 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 potential window and redox reaction in normally doped (1%) BDD and low-doped (0.1%) BDD exhibited opposite tendencies depending on the extent of sp(2) carbon. Moreover, we found that contrary to the usual expectations, low-doped BDD containing sp(2) carbon hinders electron transfer, whereas in line with expectations, normally doped BDD containing sp(2) exhibits enhanced electron transfer. Surface analyses by X-ray/ultraviolet photoelectron spectroscopy (XPS/UPS) and electrochemical methods are utilized to explain these unusual phenomena. This work indicates that the electrochemical properties of low-doped BDD containing sp(2) 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 sp(2) carbon.