Electrochemical deposition of bimetallic sulfides on novel BDD electrode for bifunctional alkaline seawater electrolysis
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-01-22 |
| Journal | Scientific Reports |
| Authors | Mingxu Li, Genjie Chu, Jiyun Gao, Xiaolei Ye, Ming Hou |
| Institutions | Franche-ComtĂ© Ălectronique MĂ©canique Thermique et Optique - Sciences et Technologies, UniversitĂ© Marie et Louis Pasteur |
| Citations | 3 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: BDD Substrates for High-Performance Seawater Electrolysis
Section titled âTechnical Documentation & Analysis: BDD Substrates for High-Performance Seawater ElectrolysisâExecutive Summary
Section titled âExecutive SummaryâThis research successfully demonstrates the use of Boron-Doped Diamond (BDD) as a highly stable, corrosion-resistant substrate for bifunctional electrocatalysts in alkaline simulated seawater electrolysis. This approach directly addresses the critical challenge of metal substrate corrosion in harsh electrochemical environments.
- Core Innovation: Utilization of 6CCVD-grade BDD as a robust platform for the electrodeposition of a novel CoFeS/Ni catalyst system, ensuring long-term stability in highly corrosive alkaline seawater.
- Enhanced Performance: The resulting CoFeS/Ni/BDD electrode achieved exceptional bifunctional activity for both the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER).
- Record Overpotentials: Achieved low overpotentials of 300 mV (HER) and 383 mV (OER) at a high industrial current density of 100 mA cm-2 in optimized 3 M KOH simulated seawater.
- Optimized Fabrication: A two-step electrodeposition process (Ni adhesion layer followed by CoFeS) was optimized, yielding best results at a Co/Fe ratio of 1.5:1 and 15 deposition cycles.
- Superior Stability: The BDD substrate enabled high stability, retaining 92.62% of OER current density and 84.31% of HER current density after 24 hours of continuous operation.
- 6CCVD Value Proposition: 6CCVD specializes in providing the high-quality, highly conductive BDD substrates (custom dimensions up to 125mm) required to replicate and scale this corrosion-resistant electrocatalysis technology.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Substrate Material | Boron-Doped Diamond (BDD) | N/A | Used for superior corrosion resistance |
| BDD Dimensions Used | 10 x 10 | mm2 | Single-sided working electrode |
| Optimal Co/Fe Concentration Ratio | 1.5:1 | N/A | Optimized for minimized overpotential |
| Optimal Electrodeposition Cycles | 15 | Cycles | CV sweep rate 5 mV/s, range -0.6 V to 0.2 V |
| Standard Electrolyte | 1 M KOH + 3.5 wt% NaCl | N/A | Alkaline simulated seawater |
| Optimized Electrolyte | 3 M KOH + 3.5 wt% NaCl | N/A | Significantly reduced overpotentials |
| HER Overpotential (Best Case) | 300 | mV | @ 100 mA cm-2 in 3 M KOH sea |
| OER Overpotential (Best Case) | 383 | mV | @ 100 mA cm-2 in 3 M KOH sea |
| OER Current Retention (24h) | 92.62 | % | Stability test in 1 M KOH real seawater |
| HER Current Retention (24h) | 84.31 | % | Stability test in 1 M KOH real seawater |
| HER Tafel Slope (Best Case) | 108.88 | mV/dec | In 3 M KOH simulated seawater |
| OER Tafel Slope (Best Case) | 110.58 | mV/dec | In 3 M KOH simulated seawater |
| Electrochemical Active Surface Area (ECSA) | 3.399 x 10-2 | mF/cm2 | CoFeS/Ni/BDD electrode |
Key Methodologies
Section titled âKey MethodologiesâThe CoFeS/Ni/BDD electrode was fabricated using a two-step electrodeposition process to ensure strong adhesion and optimal catalytic loading on the highly inert BDD substrate.
- Substrate Preparation: Single-side BDD plates (10 mm x 10 mm) were used as the base material.
- Nickel Adhesion Layer: A Ni layer was deposited onto the BDD surface via electroplating. This step was critical to improve the adhesion of the subsequent sulfide catalyst layer, overcoming the poor adhesion often observed between active materials and BDD.
- Catalyst Deposition: Cobalt-Iron Sulfide (CoFeS) was electrodeposited onto the Ni/BDD surface.
- Concentration Optimization: The concentration ratio of CoCl2 to FeCl3 was systematically varied (1:1, 1.5:1, 2:1, 3:1). The ratio of 1.5:1 was identified as optimal for minimizing HER and OER overpotentials.
- Cycle Optimization: The number of electrodeposition cycles (turns) was varied from 5 to 20. Optimal catalytic performance was achieved at 15 cycles using Cyclic Voltammetry (CV) with a scan rate of 5 mV/s.
- Electrochemical Testing: Performance was evaluated using Linear Sweep Voltammetry (LSV), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS) in a three-electrode system, utilizing Hg/HgO or Ag/AgCl as the reference electrode.
- Stability Testing: Long-term stability was assessed over 24 hours using the timed-current (i-t) method in real seawater containing 1 M KOH.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the foundational BDD materials and customization services required to replicate, scale, and advance this high-performance electrocatalysis research.
Applicable Materials
Section titled âApplicable MaterialsâThe success of this research hinges on the use of a highly conductive, corrosion-resistant substrate. 6CCVD provides the necessary material specifications:
- Boron-Doped Diamond (BDD): We supply high-quality, heavily doped BDD wafers and plates, essential for achieving the low charge transfer resistance (Rct) and high electrical conductivity demonstrated in the paper. Our BDD materials are ideal for harsh electrochemical environments, including highly alkaline and saline solutions.
- Polycrystalline Diamond (PCD): For large-scale industrial prototypes or high-throughput testing, 6CCVD offers PCD wafers up to 125 mm in diameter, providing a cost-effective path for scaling up BDD-based electrode designs.
Customization Potential
Section titled âCustomization Potentialâ6CCVDâs in-house manufacturing capabilities directly address the specific dimensional and surface requirements of advanced electrode fabrication:
| Research Requirement | 6CCVD Capability | Benefit to Researcher |
|---|---|---|
| Custom Dimensions (10 x 10 mm2) | Custom plates/wafers up to 125 mm (PCD) and custom laser cutting services. | Rapid prototyping and scaling to industrial sizes without material waste. |
| Adhesion Layer (Ni electroplating) | Internal metalization services including Au, Pt, Pd, Ti, W, and Cu. | Researchers can test alternative adhesion layers or protective coatings (e.g., Ti/Pt/Au stack) directly on the BDD substrate, simplifying their fabrication process. |
| Surface Finish (Polycrystalline structure) | Standard polishing (Ra < 5 nm for inch-size PCD) or as-grown surfaces available. | We can provide BDD with specific surface roughness tailored to maximize catalyst loading and ECSA, crucial for optimizing the cauliflower-like Ni layer morphology. |
| Doping Control | Precise control over Boron doping levels during MPCVD growth. | Ensures the high conductivity necessary for minimizing overpotential and maximizing charge transfer kinetics during HER and OER. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists and engineers offers comprehensive technical consultation to accelerate research timelines:
- Material Selection: Assistance in selecting the optimal BDD doping concentration and thickness (SCD: 0.1 ”m - 500 ”m; PCD: 0.1 ”m - 500 ”m) for similar alkaline seawater electrolysis projects.
- Surface Preparation: Guidance on pre-treatment and polishing techniques to enhance the adhesion and uniformity of electrodeposited layers (Ni, CoFeS).
- Global Logistics: Reliable global shipping (DDU default, DDP available) ensures rapid delivery of custom BDD substrates worldwide.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.