Heavy metals determination using various in situ bismuth film modified carbon-based electrodes
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-04-01 |
| Journal | Acta Chimica Slovaca |
| Authors | Jozef Sochr, Martina MachkovĂĄ, ÄœubomĂr MachyĆĂĄk, FrantiĆĄek Äacho, ÄčubomĂĆÌ Ć vorc |
| Institutions | Czech Academy of Sciences, Institute of Analytical Chemistry, Slovak University of Technology in Bratislava |
| Citations | 13 |
| Analysis | Full AI Review Included |
Technical Analysis & Documentation: MPCVD Diamond for Advanced Electrochemistry
Section titled âTechnical Analysis & Documentation: MPCVD Diamond for Advanced ElectrochemistryâExecutive Summary
Section titled âExecutive SummaryâThis document analyzes the research on using in situ bismuth film modified carbon-based electrodes for heavy metal determination, focusing on the critical role of Boron-Doped Diamond (BDD) substrates.
- Optimal Substrate Identified: The Boron-Doped Diamond Electrode (BDDE) modified with Bismuth Film (BiF) was proven to be the superior substrate for Differential Pulse Anodic Stripping Voltammetry (DPASV) compared to Glassy Carbon (GCE) and Carbon Paste (CPE).
- Enhanced Sensitivity: The BiF-BDDE modification significantly enhanced the deposition and stripping processes of heavy metal cations (Zn2+, Cd2+, Pb2+), leading to lower Limits of Detection (LODs).
- High Accuracy Validation: The developed electrochemical method achieved excellent agreement with the reference spectral method (High-Resolution Continuum Source Atomic Absorption Spectroscopy), demonstrating a recovery of 95.8% for Pb2+ in certified reference material.
- Routine Application Ready: The BiF-BDDE sensor is highlighted as a suitable, non-toxic, and environmentally friendly alternative to mercury electrodes for routine, sensitive analysis of heavy metals in water and wastewater samples.
- Key Operational Parameters: Optimal performance was achieved using in situ deposition at -1.4 V for 120 s in a pH 4.5 Acetate Buffer containing 0.1 mmol l-1 Bi3+.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental results and methodology:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Electrode Substrate | Boron-Doped Diamond (BDDE) | N/A | Optimal working electrode material |
| BDDE Diameter | 3 | mm | Physical dimension used in the study |
| BDDE Resistivity | 75 | mΩcm | Electrical property of the commercial BDDE |
| Boron/Carbon Ratio (B/C) | 1000 | ppm | Doping concentration in the BDDE |
| Supporting Electrolyte | 0.1 | mol l-1 | Acetic Buffer (AB) |
| Electrolyte pH | 4.5 | N/A | Optimized to prevent Bi3+ hydrolysis |
| Bi3+ Concentration | 0.1 | mmol l-1 | Required for in situ BiF preparation |
| Deposition Potential (Edep) | -1.4 | V | Optimal potential vs. Ag/AgCl/3 mol l-1 KCl |
| Deposition Time (tdep) | 120 | s | Optimal time for BiF formation on all substrates |
| Simultaneous LOD (Cd2+) | 12 | nmol l-1 | Lowest LOD achieved using BiF-BDDE |
| Simultaneous LOD (Pb2+) | 34 | nmol l-1 | LOD achieved using BiF-BDDE |
| Reference Method Recovery (Pb2+) | 95.8 | % | Accuracy validation in certified reference material |
Key Methodologies
Section titled âKey MethodologiesâThe experiment utilized Differential Pulse Anodic Stripping Voltammetry (DPASV) combined with in situ bismuth film modification.
- Substrate Selection and Pre-treatment: Three carbon-based substrates were tested: BDDE, GCE, and CPE. BDDE was pre-treated via sonication in a methanol:water (1:1 v/v) mixture for 5 min, while GCE and CPE were mechanically polished with 0.3 ”m alumina slurry.
- Electrochemical Cleaning: All electrodes were conditioned by stripping Bi at +0.5 V in 0.1 mol l-1 Acetate Buffer (AB) for 5 min.
- Electrolyte Preparation: The supporting electrolyte was 0.1 mol l-1 AB solution adjusted to pH 4.5. For in situ modification, 0.1 mmol l-1 Bi3+ ions (from solid Bi(NO3)3) were added directly to the electrolyte.
- Deaeration: Dissolved oxygen was eliminated by bubbling gaseous nitrogen (N2) for 10 min prior to measurement to reduce background interference.
- DPASV Parameters: Instrumental settings included a potential step of 5 mV, a modulation amplitude of 25 mV, and a modulation time of 50 ms.
- Optimized Deposition: Simultaneous deposition of heavy metals and the bismuth film occurred at the optimized potential of -1.4 V for 120 s.
- Quantification: Heavy metal concentrations in real water samples were quantified using the standard addition method, validated against High-Resolution Continuum Source Atomic Absorption Spectroscopy (HR CS ETAAS).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is the premier supplier of MPCVD diamond materials necessary to replicate and advance this high-performance electrochemical sensing technology. The superior performance of the BDDE in this study confirms the materialâs advantage in electroanalysis, particularly where low background current and wide potential windows are required.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend this research, 6CCVD recommends the following materials, tailored for high-sensitivity electrochemistry:
| 6CCVD Material | Specification | Application Relevance |
|---|---|---|
| Conductive Boron-Doped Diamond (BDD) | Heavy doping (B/C ratio > 1000 ppm), Resistivity < 75 mΩcm. | Direct replacement for the optimal substrate, ensuring low resistance and wide potential window for DPASV. |
| Polycrystalline Diamond (PCD) | Thickness 0.1 ”m - 500 ”m. | Ideal for large-scale sensor array fabrication and high-volume production of BiF-BDDE sensors. |
| Ultra-Polished SCD | Surface roughness Ra < 1 nm. | For fundamental research requiring the most pristine, reproducible surface for studying in situ Bi film nucleation and growth kinetics. |
Customization Potential
Section titled âCustomization PotentialâThe study utilized small, 3 mm diameter electrodes. 6CCVDâs advanced manufacturing capabilities allow researchers and engineers to move beyond standard sizes and integrate BDDE into complex systems:
- Custom Dimensions: We provide BDD plates and wafers up to 125 mm (PCD) for high-density array fabrication. We offer precision laser cutting and shaping services to produce custom electrode geometries (e.g., microelectrodes, rings, or the 3 mm discs used in this study).
- Integrated Metalization: For seamless integration into potentiostats and microfluidic platforms, 6CCVD offers in-house metalization services. We can deposit robust contact layers (e.g., Ti/Pt/Au, W, Cu) directly onto the BDD surface, ensuring stable, low-resistance electrical connections critical for reproducible voltammetry.
- Thickness Control: We offer precise control over BDD film thickness (0.1 ”m to 500 ”m), allowing optimization for specific sensor designs, whether thin films on silicon or thick, self-supporting plates.
Engineering Support
Section titled âEngineering SupportâThe successful application of BiF-BDDE for heavy metal sensing via DPASV is a prime example of diamondâs utility in green electroanalytical chemistry.
6CCVDâs in-house PhD team specializes in material science and electrochemical applications. We provide expert consultation to assist clients in:
- Material Selection: Choosing the optimal BDD doping level and resistivity for specific stripping voltammetry or sensor projects.
- Surface Preparation: Advising on polishing and pre-treatment protocols necessary to achieve the ultra-clean surfaces required for highly reproducible in situ film deposition.
- Scaling and Integration: Designing custom BDD components for commercial sensor development and high-throughput water quality monitoring systems.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract The proposed work deals with the utilization of three carbon-based electrode substrates such as boron-doped diamond, glassy carbon and carbon paste for the preparation of in situ bismuth film modified electrodes. Such modified electrodes were subsequently used for the differential pulse anodic stripping voltammetric determination of heavy metal cations (Zn 2+ , Cd 2+ and Pb 2+ ) individually and simultaneously using similar experimental conditions (0.1 mol l â1 acetic buffer solution of pH 4.5 as supporting electrolyte with the addition of 0.1 mmol l â1 Bi 3+ , deposition potential of â1.4 V and deposition time of 120 s). The results showed that the modification step mostly enhanced the deposition and stripping process of studied cations when compared to the bare electrode substrates. A boron-doped diamond electrode was selected as the substrate for modification and the procedure was applied to the real sample analysis including water sample (certified reference material) and wastewater sample. Using the standard addition method the concentrations of particular heavy metals were quantified and the determined values were in a good agreement with those obtained by the reference method â high resolution atomic absorption spectroscopy with electrothermal atomisation and continual radiation source. This fact highlights that the developed in situ bismuth film modified boron-doped diamond electrode is a suitable electrochemical sensor to be applied to routine analysis of water samples containing heavy metals.