Tailored design of boron-doped diamond electrodes for various electrochemical applications with boron-doping level and sp² -bonded carbon impurities

Abstract

The effects of sp2‐bonded carbon impurities on the electrochemical properties of boron‐doped diamond were investigated in moderately ([B] < 1020 cm−3) and heavily ([B] > 1021 cm−3) boron doping levels. Significant influences of sp2‐bonded carbon impurities, which show glassy carbon‐like electrochemical properties after anodic oxidation, were observed in heavily boron‐doped diamond. This indicated that the significant effects of enhanced adsorption properties were possibly caused by surface relaxation of the strains induced by heavy boron doping and sp2‐bonded carbon impurities. On the other hand, their durability was still similar to diamond electrodes rather than glassy‐carbon electrodes because of the low fraction of sp2‐bonded carbon impurities. Such “active” diamond electrodes are much less suitable for wastewater treatment than ordinary diamond electrodes due to a different oxygen‐evolution mechanism. On the other hand, “active” BDD electrodes have a much higher efficiency for electrochemical ozone production than other BDD electrodes. The electrode properties of BDD can be designed by controlling the boron doping level and introducing the sp2‐bonded carbon impurities. The guidelines proposed in this study can be used effectively to design electrodes according to their individual application, such as for use as electrochemical sensors, in wastewater treatment or electrochemical ozone production.

Role of sp3/sp2 ratio on the electrocatalytic properties of boron-doped diamond electrodes: A mini review

“…The most noticeable effect related to the sp 3 /sp 2 ratio on BDD is the variation on the potential window [2,23]. It tends to decrease when an increase on the boron doping level and sp 2 -carbon impurities is attained on BDD; achieving similar voltammetric features that glassy carbon (GC) electrode (Fig.…”

“…In terms of the non-diamond sp 2 carbon, as the boron content in a film increases, the size of the crystallites decreases, and consequently, impurity phase appears, affecting the electron-transfer kinetics of redox systems differently as well as background current and potential window. In this frame, the boron doping concentration [2,21,23] could be controlled during BDD synthesis, regulating the distribution of sp 2 -sp 3 carbon forms on the final structure of the films [18].…”

“…Nevertheless, recent results have demonstrated that EO is strongly influenced by BDD synthesis characteristics [2,[17][18][19][20][21][22][23][24][25], particularly the ratio of sp 3 /sp 2 carbon.…”

Assessment of Boron Doped Diamond Electrode Quality and Application to <em>In Situ</em> Modification of Local pH by Water Electrolysis

“…Note for some applications, NDC presence is seen as advantageous 13 . Furthermore, if the material does not contain sufficient boron it will behave as a p-type semi-conductor and show reduced sensitivity to redox species in the reductive potential window, where the material is most depleted of charge carriers 7 .…”

Recovery of copper from dilute cupric sulfate solution by electrodeposition method using boron‐doped diamond electrodes

“…Due to their properties, BDD electrode has been applied for the electrochemical sensors [13], wastewater treatments [14], and the organic electrolytic synthesis [15]. On the other hand, electrochemical properties of BDD electrode was found to be modified by adjusting boron doping level and/or containing sp 2 carbon impurities [16]. In this work, two types of BDD electrodes with different boron doping level were prepared, and potentiostatic deposition of Cu was carried out using BDD electrodes in a dilute cupric sulfate solution as a model wastewater in order to investigate the suitable boron doping level for the recovery of Cu from wastewater.…”