Electrolytic Treatment Characteristics of Boron-doped Nanocrystalline Diamond/Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2017-01-01 |
| Authors | Takumi Takenaga, Masaya Onishi, Daisuke Fujimoto, Y. Nojiri, Takeshi Hara |
| Institutions | National Institute of Technology, Ariake College, National Institute of Technology, Sasebo College |
| Citations | 2 |
| Analysis | Full AI Review Included |
6CCVD Technical Documentation: Boron-Doped Diamond for High-Performance Electrolytic Treatment
Section titled â6CCVD Technical Documentation: Boron-Doped Diamond for High-Performance Electrolytic TreatmentâExecutive Summary
Section titled âExecutive SummaryâThis research validates the superior performance of Boron-Doped Diamond (BDD) materials as anodes for the electrolytic degradation of recalcitrant organic pollutants, specifically 4-Nitrophenol (4-NP). 6CCVD specializes in manufacturing the high-quality, scalable BDD required to replicate and exceed these results.
- Superior Performance: B-doped NCD/a-C composite films demonstrated an excellent 4-NP reduction rate (31% after 60 min), significantly surpassing conventional noble-metal Pt electrodes (14% reduction).
- Electrochemical Stability: The diamond films exhibited the critical characteristics of BDD electrodes: a wide electrical potential window and an extremely low background current, essential for high-efficiency electrolysis.
- Material Comparison: Commercial BDD electrodes (likely MPCVD-grown) achieved a higher reduction rate (36%) than the CAPD-prepared composite films (31%), confirming that pure, high-quality BDD offers maximum performance.
- Application Focus: The findings strongly support the use of BDD anodes for industrial wastewater treatment, electrosynthesis, and advanced electrochemical sensing applications.
- 6CCVD Advantage: 6CCVD provides high-purity, scalable MPCVD BDD wafers (SCD and PCD) up to 125mm, offering superior performance, stability, and customization compared to the composite films studied.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and methodology:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Film Thickness | 1.4 | ”m | B-doped NCD/a-C film deposited by CAPD |
| Substrate Temperature | Room Temperature | °C | Maintained during CAPD deposition |
| Target Composition | Graphite (5 at.% B) | - | Boron concentration in target material |
| Arc Voltage | 100 | V | Applied to the coaxial arc plasma gun |
| Pulsed Discharge Rate | 5 | Hz | Repetition rate of pulsed discharges |
| NCD Crystallite Diameter | 40 | nm | Calculated via Scherrer equation from the diamond (111) peak |
| Electrolyte Concentration | 0.20 | mol/L | Na2SO4 solution used for treatment |
| Current Density | 1.5 | A/dm2 | Applied during electrolytic treatment |
| 4-NP Reduction Rate (BDD) | 36 | % | After 60 min treatment (Commercial BDD anode) |
| 4-NP Reduction Rate (NCD/a-C) | 31 | % | After 60 min treatment (CAPD B-doped anode) |
| 4-NP Reduction Rate (Pt) | 14 | % | After 60 min treatment (Commercial Pt anode) |
| Electrode Area | 15 | mm2 | Used for CV and batch-type electrolytic treatment |
Key Methodologies
Section titled âKey MethodologiesâThe B-doped nanocrystalline diamond/amorphous carbon (NCD/a-C) composite films were fabricated using a physical vapor deposition (PVD) technique, and their electrochemical properties were rigorously tested:
- Film Fabrication: Films were deposited using Coaxial Arc Plasma Deposition (CAPD) onto low-resistivity p-type Si (100) substrates.
- Source Material: A graphite target containing 5 at.% B was used to achieve boron doping.
- Deposition Conditions: Deposition occurred under high vacuum (< 10-3 Pa) and at room temperature, circumventing the high temperatures (> 800 °C) and hydrogen requirements typical of conventional CVD.
- Structural Analysis: X-ray Diffraction (XRD) using a semiconductor counter detector confirmed the presence of the diamond (111) peak, allowing calculation of the 40 nm crystallite diameter. Raman spectroscopy confirmed the composite nature (NCD/a-C) via the broad G-band (1580 cm-1).
- Electrochemical Characterization: Cyclic Voltammetry (CV) was performed in 1.0 mol/L H2SO4 to verify the wide potential window and low background current, confirming p-type semiconducting behavior.
- Electrolytic Treatment: A batch-type system was used, employing the B-doped NCD/a-C film as the anode and stainless steel as the cathode, separated by 5.0 mm.
- Performance Metric: Degradation of 4-Nitrophenol (4-NP) aqueous solution (100 mgTOC/L) was monitored over 60 minutes using UV-vis spectrophotometry, tracking the decrease in absorbance at 400 nm.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research confirms that BDD is the optimal material for advanced electrolytic applications. While the CAPD method offers unique low-temperature fabrication, the resulting NCD/a-C composite film showed performance inferior to commercial BDD. 6CCVD provides high-purity, scalable MPCVD BDD that delivers maximum efficiency and stability for industrial applications.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this research with maximum performance, 6CCVD recommends the following materials:
- Heavy Boron-Doped Polycrystalline Diamond (BDD-PCD): This material provides the highest electrochemical activity, stability, and scalability for large-area anode applications, directly matching the superior performance benchmark (36% reduction rate) cited in the paper.
- Optical Grade Single Crystal Diamond (SCD): For high-precision electrochemical sensors or micro-electrode arrays requiring ultra-low defect density and Ra < 1 nm surface finish.
- Custom BDD Thickness: We offer BDD layers from 0.1 ”m up to 500 ”m, allowing researchers to optimize the active layer thickness for specific current density requirements.
Customization Potential
Section titled âCustomization PotentialâThe small, 15 mm2 electrode size used in the study is insufficient for industrial scale-up. 6CCVD eliminates this limitation through advanced manufacturing capabilities:
| Research Requirement | 6CCVD Capability | Benefit to Client |
|---|---|---|
| Small Electrode Area (15 mm2) | Large Area PCD Wafers: Up to 125 mm diameter. | Enables industrial-scale electrolytic cell design and high throughput. |
| Substrate (Si) | Custom Substrates & Freestanding: BDD on Si, Mo, W, or thick, freestanding BDD plates (up to 10 mm). | Allows integration into diverse reactor designs and thermal management systems. |
| Electrical Contact | Custom Metalization: Internal capability for Au, Pt, Pd, Ti, W, and Cu stacks. | Ensures robust, low-resistance electrical contacts for high current density applications (e.g., Ti/Pt/Au stack). |
| Surface Finish | Precision Polishing: Polycrystalline surfaces polished to Ra < 5 nm (inch-size). | Reduces fouling and improves mass transport kinetics at the electrode interface. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists and engineers specializes in optimizing diamond properties for electrochemical environments. We provide comprehensive support for projects involving:
- Electrolytic Degradation: Material selection and doping level optimization for maximum hydroxyl radical generation and pollutant destruction (e.g., phenolic pollutants, recalcitrant substances).
- Electrosynthesis: Tailoring BDD conductivity and surface termination for specific synthetic pathways.
- Sensor Development: Providing ultra-smooth SCD or highly conductive BDD-PCD for high-sensitivity electrochemical sensors.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Boron-doped nanocrystalline diamond amorphous carbon composite (NCD/a-C) films were fabricated by coaxial arc plasma deposition (CAPD). Electrical conductivity measurements and thermal analysis confirmed that the deposited films exhibited p-type semiconductor behavior. Cyclic voltammetry measurements of deposited films showed a wide electrical potential window and an extremely low background current. 4-Nitrophenol (4-NP) aqueous solution, which is a recalcitrant substance, was decomposed via electrolytic treatment using a batch-type electrolytic treatment system wherein the B-doped NCD/a-C films were used as anodes. UV-vis spectra showed that the absorbance of 4-NP at 400 nm decreased with increasing electrolytic treatment time. This behavior implies that the B-doped NCD/a-C films deposited by CAPD are potential electrode materials for use in the electrolytic degradation of recalcitrant substances.