Boron doped diamond/metal nanocatalyst hybrid electrode arrays for analytical applications
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2017-05-01 |
| Authors | Emmanuel Scorsone, Dounia Belghiti, Massiel Habchi, P. Bergonzo |
| Institutions | Commissariat Ă lâĂnergie Atomique et aux Ănergies Alternatives, CEA LIST |
| Citations | 1 |
| Analysis | Full AI Review Included |
MPCVD Diamond Technical Analysis: Hybrid BDD Nano-Catalyst Electrode Arrays for Contaminant Detection
Section titled âMPCVD Diamond Technical Analysis: Hybrid BDD Nano-Catalyst Electrode Arrays for Contaminant DetectionâThis document analyzes the research published by Scorsone et al. concerning the fabrication and testing of Boron Doped Diamond (BDD)/Metal Nanocatalyst Hybrid Electrode Arrays. The analysis connects the reported specifications and methodologies directly to the advanced MPCVD diamond solutions available from 6CCVD.
Executive Summary
Section titled âExecutive SummaryâThe reported study demonstrates a highly effective method for developing selective electrochemical sensor arrays using custom-engineered MPCVD Boron Doped Diamond (BDD) substrates.
- Core Achievement: Development of a multi-sensor array using four BDD electrodes, each modified with a different metal or metal alloy nanoparticle (e.g., BDD, BDD-Pt, BDD-Ir, BDD-PtIr).
- Material Foundation: The electrodes utilize heavily Boron-doped diamond (2.1021 at.cm-3) grown via MPECVD, enabling a wide potential window and high resilience required for analytical sensing.
- Nanocatalyst Fabrication: A novel two-step process involving Physical Vapor Deposition (PVD) of a thin metal film (2-3 nm) followed by high-temperature hydrogen plasma de-wetting successfully produced well-adhered nanoparticles (~10 nm size).
- Enhanced Selectivity: The BDD-PtIr alloy nanoparticles exhibited superior catalytic activity compared to single-metal nanoparticles or bare BDD, crucial for the highly sensitive detection and discrimination of multiple contaminants (DMMP, H2O2, Imidacloprid).
- Application Demonstrated: The array was successfully tested for online detection and classification of contaminants in tap water using chronoamperometry and Principal Component Analysis (PCA).
- 6CCVD Value Proposition: 6CCVD can replicate and optimize the critical BDD substrate synthesis and the necessary metal precursor deposition using its internal MPCVD and metalization capabilities.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Diamond Material | Boron Doped Diamond (BDD) | N/A | Electrochemical working electrode material |
| Growth Method | MPECVD | N/A | Microwave Plasma Enhanced CVD |
| Substrate Size (Pre-Cleaving) | 4 inches | Diameter | Highly doped <100> silicon |
| BDD Film Thickness | 500 | nm | Measured via optical interferometry |
| Boron Doping Concentration | 2.1021 | at.cm-3 | Determined by SIMS, heavy doping |
| Electrode Dimensions | 1 | cm2 | Individual BDD electrodes, cleaved post-growth |
| Nanocatalyst Size (Mean) | 10 | nm | Particle size after de-wetting (SEM/SAXS) |
| Precursor Film Thickness | 2-3 | nm | Initial metal film thickness (Pt, Ir, Au, Rh) |
| Sputtering Pressure (Ar) | 6.10-3 | mbar | PVD chamber pressure |
| Sputtering RF Power | 50 | W | Power applied for PVD metal deposition |
| Sputtering Rate | 5 to 15 | nm.min-1 | Dependent on metal type |
| De-wetting Power | 900 | kW | Hydrogen plasma applied for 10 min |
| De-wetting Pressure | 40 | mbar | Hydrogen plasma chamber pressure |
| Measurement Voltage | -0.1 | V | Polarization voltage vs. pseudo-reference electrode |
| Flow Rate (Tap Water) | 300 | mL.min-1 | Used in the dedicated flow cell |
Key Methodologies
Section titled âKey MethodologiesâThe successful fabrication of the hybrid electrode arrays relies on precise control over two distinct processes: MPCVD diamond growth and subsequent metal nanocatalyst deposition.
-
BDD Substrate Growth (MPCVD):
- BDD film (500 nm thick) was grown onto 4-inch highly doped <100> silicon substrates using a proprietary Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) process.
- The films were intentionally heavily doped with Boron to a concentration of 2.1021 at.cm-3 to ensure high conductivity and a wide electrochemical window.
- The wafer was cleaved to produce individual 1 cm2 electrodes.
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Thin Metal Film Deposition (PVD):
- Thin films (2-3 nm) of metal precursors (Pt, Ir, Au, Rh, or alloys) were deposited onto the BDD surface.
- This was achieved using Physical Vapor Deposition (PVD) via RF-sputtering, utilizing 50 W RF power and an Argon chamber pressure of 6.10-3 mbar.
-
Nanoparticle Formation (De-wetting):
- The metal-coated BDD samples were exposed to a Hydrogen plasma in a dedicated diamond growth reactor for 10 minutes.
- Key parameters for this de-wetting step were: 900 kW microwave power and 40 mbar pressure.
- This thermal treatment caused the metal thin film to restructure, forming well-adhered nanoparticles with a mean size of approximately 10 nm, verified by SEM and SAXS.
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Electrochemical Testing:
- Four specialized working electrodes (WE: BDD, BDD-Pt, BDD-Ir, BDD-PtIr) were integrated into a 3D-printed flow cell setup, along with unmodified BDD counter (CE) and pseudo-reference (RE) electrodes.
- Measurements were conducted using chronoamperometry at -0.1 V (vs. pseudo-RE) to detect and discriminate contaminants in flowing tap water (300 mL.min-1).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the foundational materials and advanced customization services required to replicate and scale this highly successful research endeavor, particularly for the development of multi-sensor arrays and e-tongue applications.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend the analytical performance achieved in this paper, researchers require heavily doped, high-quality BDD electrodes capable of high electron transfer rates.
| 6CCVD Product Recommendation | Specification Match/Advantage | Customization Potential |
|---|---|---|
| Heavy Boron Doped Diamond (BDD) Wafers | Doping Level: We provide BDD with doping densities up to the 1021 at.cm-3 range, matching the required conductivity (2.1021 at.cm-3). | Available as plates or wafers. We offer custom thicknesses from 0.1 ”m up to 500 ”m (as used in the paper) on Si, Quartz, or dedicated high-purity Diamond substrates. |
| High-Purity Polycrystalline Diamond (PCD) | Platform Size: While the paper used 1 cm2 pieces, 6CCVD can supply large-area PCD up to 125mm (5 inches) for high-throughput array fabrication. | Excellent polishing capability (Ra < 5nm) ensures optimal surface quality for subsequent thin-film PVD and de-wetting processes. |
| Custom Metalization Services | PVD Match: The study relies on precise deposition of Pt, Ir, and alloys. 6CCVD offers internal, highly controlled PVD/sputtering and e-beam capabilities. | We provide uniform thin-film deposition of Pt and Ir (and Pd, Au, Ti, W, Cu) at nanometer thicknesses (2-3 nm range) directly onto BDD, serving as the required precursor for the de-wetting step. |
Customization Potential
Section titled âCustomization PotentialâThe development of reliable sensor arrays often requires tight dimensional control and specific surface modifications.
- Custom Dimensions and Cleaving: The paper utilized 1 cm2 electrodes cleaved from a 4-inch wafer. 6CCVD offers precision laser cutting, scribing, and cleaving services to deliver BDD substrates in any custom shape or size required for microfluidic or sensor integration (e.g., 3D printed flow cells).
- Targeted Metal Layering: 6CCVD can facilitate the precise deposition of alloy precursors (e.g., Pt/Ir layering) prior to the researcherâs de-wetting step, ensuring the precursor materials for the high-performance BDD-PtIr system are available in ultra-high purity.
- Surface Preparation: For advanced electrode arrays, 6CCVD can provide atomically smooth SCD (Ra < 1nm) or PCD (Ra < 5nm) surfaces, minimizing background noise and maximizing adhesion uniformity prior to PVD.
Engineering Support
Section titled âEngineering SupportâThe successful demonstration of the BDD-PtIr alloyâs superior catalytic properties for online contaminant detection confirms diamondâs role as the premier electrode material for environmental and industrial sensing.
6CCVDâs in-house team of PhD material scientists and engineers specializes in diamond chemistry and electrochemistry. We can assist researchers in:
- Optimizing Boron Doping: Tailoring the precise doping level to optimize the potential window and conductivity for specific redox reactions (e.g., DMMP reduction or H2O2 reduction).
- Substrate Selection: Advising on the optimal BDD thickness and substrate (Si, fused silica, or diamond) to meet mechanical, thermal, and electrical requirements for multi-sensor array deployment.
- Interface Engineering: Consulting on metalization strategies, including adhesion layers and capping layers, for durable nano-catalyst deposition in complex applications like water quality monitoring and e-tongue systems.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Conference of 2017 ISOCS/IEEE International Symposium on Olfaction and Electronic Nose, ISOEN 2017 ; Conference Date: 28 May 2017 Through 31 May 2017; Conference Code:129051