This work aims to study the effect of the distinctive chemical and structural surface features of boron doped diamond (BDD) anodes on their electrochemical performance for perfluorooctanoic acid (PFOA) degradation. Commercial BDD anodes were compared: (i) a microcrystalline (MCD) coating on silicon; and (ii) an ultrananocrystalline (UNCD) coating on niobium. MCD gave rise to the complete PFOA (0.24 mmol L⁻¹) degradation in 4 h, at any applied current density in the range 1–5 mA cm⁻². On the contrary, only 21% PFOA removal was achieved when using UNCD at 5 mA cm⁻² under comparable experimental conditions. Similarly, the total organic carbon (TOC) was reduced by 89% using MCD, whereas only 13% TOC decrease was obtained by UNCD. In order to explain the dissimilar electrochemical activities, the morphological and chemical characterization of the electrode materials was developed by means of FESEM microscopy, XPS and Raman spectroscopy. The UNCD anode surface showed characteristic ultrananocrystalline grain size (2–25 nm), higher boron doping and greater content of H-terminated carbon, whereas the MCD anode was less conductive but contained higher sp³ carbon on the anode surface. Overall, the MCD electrode features allowed more efficient PFOA electrolysis than the UNCD anode. As a result of their distinctive performance, the energy needed for the maximum PFOA degradation (after 4 h) using MCD anode was only 1.4 kWh m⁻³, while the estimated energy consumption for the UNCD anode would be 37-fold higher. It is concluded that the use of the MCD anode involves considerable energy costs savings.

这项工作旨在研究硼掺杂金刚石（BDD）阳极独特的化学和结构表面特征对其全氟辛酸（PFOA）降解电化学性能的影响。比较了商用BDD阳极：（i）硅上的微晶（MCD）涂层；（ii）铌上的超纳米晶（UNCD）涂层。在1至5 mA cm ^-2范围内的任何施加电流密度下，MCD均可在4小时内完全降解PFOA（0.24 mmol L ^-1）。相反，在5 mA cm ^-2下使用UNCD时，只有21％的PFOA去除率在可比较的实验条件下。同样，使用MCD，总有机碳（TOC）降低了89％，而UNCD仅降低了13％。为了解释不同的电化学活性，借助于FESEM显微镜，XPS和拉曼光谱法开发了电极材料的形态和化学表征。UNCD阳极表面显示出特征性的超纳米晶粒尺寸（2–25 nm），较高的硼掺杂量和较高的氢封端碳含量，而MCD阳极的导电性较低，但sp ³较高阳极表面的碳。总体而言，MCD电极的特性使PFOA电解比UNCD阳极更有效。由于其出色的性能，使用MCD阳极实现最大PFOA降解（4小时后）所需的能量仅为1.4 kWh m ^-3，而UNCD阳极的估计能耗将高出37倍。结论是，使用MCD阳极可节省大量能源成本。