Intermittent‐contact Scanning Electrochemical Microscopy (IC‐SECM) as a Quantitative Probe of Defects in Single Crystal Boron Doped Diamond Electrodes

Abstract

We demonstrate, for the first time, the use of electrochemical imaging to identify defect and defect free areas in single crystal boron doped diamond (BDD) electrodes. Specifically, we show that defects contain different boron dopant concentrations than the surrounding single crystal matrix and that these variations can be visualized using intermittent contact−scanning electrochemical microscopy (IC‐SECM). The measured IC‐SECM tip currents provide quantitative information on the rates of electron transfer across the single crystal BDD electrodes, which correlate with variations in boron doping levels. In some instances, IC‐SECM outperforms alternative methods such as Raman microscopy and cathodoluminescence imaging, due to its intrinsic surface‐sensitivity, expanding the application and impact of electrochemical microscopy for materials characterization. The results obtained, and procedure outlined, are particularly valuable for the assessment and screening of single crystal BDD electrodes.

Scanning Probe Microscopy for Nanoscale Electrochemical Imaging

“…Imaging of gold bands on a glass substrate demonstrates the capabilities of this method for simultaneous topography and activity mapping . IC-SECM was applied to quantify the rates of electron transfer across single crystal boron-doped diamond (BDD) electrodes …”

“…45 IC-SECM was applied to quantify the rates of electron transfer across single crystal boron-doped diamond (BDD) electrodes. 46 Scanning electrochemical impedance microscopy (SEIM) is a type of alternating current (ac) SECM. SEIM allows the extraction of many parameters, including capacitance and charge transfer resistance.…”

Interrogating the Surface Intermediates and Water Oxidation Products of Boron‐Doped Diamond Electrodes with Scanning Electrochemical Microscopy

“…Scanning electrochemical microscopy (SECM) is a powerful tool to spatially and temporally resolve local reactivity at interfaces and has been recently applied to heterogeneous electron transfer at BDD electrodes . Various SECM modes have been used to determine outer sphere reactivity in single crystal and polycrystalline BDD electrodes, collect H 2 O 2 and other ROS as water oxidation products, and determine solvent windows of differently doped and terminated facets . Here, we employ the collection mode of SECM to qualify water oxidation products and how they change with pH and electrolyte.…”

Fabrication of a single sub-micron pore spanning a single crystal (100) diamond membrane and impact on particle translocation

“…[76] Furthermore, with layered diamond growth, it is possible to produce single crystal devices which have conducting diamond grown on top of insulating diamond. [77] This makes it then possible to build in electric-field enhancement [78,79] capabilities that could facilitate analyte detection into the singlenucleotide base resolution.…”