Preparation of boron doped diamond modified by iridium for electroreduction of carbon dioxide (CO2)

At a Glance

Metadata	Details
Publication Date	2017-04-01
Journal	IOP Conference Series Materials Science and Engineering
Authors	Andi Muhammad Ichzan, Jarnuzi Gunlazuardi, Tribidasari A. Ivandini
Institutions	University of Indonesia
Citations	5
Analysis	Full AI Review Included

Technical Documentation and Analysis: IrOx-Modified BDD for CO₂ Electroreduction

Executive Summary

This documentation analyzes the application of Iridium oxide-modified Boron-Doped Diamond (IrOx-BDD) electrodes for high-selectivity electrochemical reduction of carbon dioxide (CO₂RR).

Core Achievement: Successful modification and characterization of Boron-Doped Diamond (BDD) with electroactive Iridium oxide (IrO₂) nanoparticles.
Methodology: Electrochemical deposition was achieved efficiently via Chronoamperometry at +1.2 V (vs. Ag/AgCl), building upon the inherent stability of the BDD substrate.
Material Stability: Cyclic Voltammetry confirmed the wide potential window and high electrochemical stability of the BDD substrate, enabling redox processes without contamination peaks.
Catalytic Potential: The IrOx-BDD composite electrode is demonstrated to be promising for CO₂ electroreduction, specifically targeting the formation of multi-carbon (C₂₊) organic compounds like acetic acid.
Validation: Deposition and formation of IrO₂ were confirmed by XPS analysis, identifying a specific peak at 86 eV, alongside morphological verification via FE-SEM.
6CCVD Value: This research reinforces the critical need for high-quality, high-stability BDD electrodes, a core offering where 6CCVD provides custom dimensions and specific doping levels for demanding electrochemical applications.

Technical Specifications

The following table extracts key parameters and performance metrics detailed in the research for the fabrication and characterization of the IrOx-BDD electrodes.

Parameter	Value	Unit	Context
Substrate Material	Boron-Doped Diamond (BDD)	N/A	Working Electrode
Modification Species	Iridium Oxide (IrO₂)	N/A	Electrocatalytic coating
CV Potential Window (Unmodified BDD)	-1.0 to +1.5	V	vs. Ag/AgCl, confirming stability
CV Scan Rate	100	mV/s	Standard characterization rate
Iridium Precursor Concentration	0.5	mM	H₂IrCl₆ in KNO₃ electrolyte
Precursor Aging Temperature	80	°C	Heated for specified time (1 hr)
Deposition Technique	Chronoamperometry	N/A	IrOx deposition onto BDD
Deposition Potential	+1.2	V	vs. Ag/AgCl, applied for 10 minutes
IrO₂ Confirmation Peak (XPS)	86	eV	Binding Energy for Iridium Oxide
Intended CO₂RR Product Class	C₂₊ Organics	N/A	Target high-value chemicals (e.g., acetic acid)

Key Methodologies

The preparation of the high-performance IrOx-BDD electrode relied on precise electrochemical control and material characterization:

BDD Substrate Baseline Testing: Cyclic Voltammetry (CV) was initially performed on the bare BDD electrode in 0.1 M KNO₃ to confirm a clean, stable potential window spanning from -1.0 V to +1.5 V (vs. Ag/AgCl).
Iridium Solution Preparation: The modification solution, composed of 0.5 mM H₂IrCl₆ and 0.1 M KNO₃ (1:1 ratio), was prepared and aged by heating the closed vial at 80 °C for 1 hour.
Electrochemical Deposition: The BDD substrate was modified using Chronoamperometry by applying a constant potential of +1.2 V (vs. Ag/AgCl) for 10 minutes, resulting in IrOx deposition.
Reproducibility Testing: Repeating the CV process for 10 cycles demonstrated good electrochemical reproducibility and confirmed that the deposition process reached saturation on the BDD surface.
Surface Analysis: Confirmation of IrO₂ deposition was achieved using X-ray Photoelectron Spectroscopy (XPS), which identified the characteristic IrO₂ peak at 86 eV, and Field Emission Scanning Electron Microscopy (FE-SEM), which provided morphological evidence of Ir particles.

6CCVD Solutions & Capabilities

The development of advanced electrocatalytic interfaces, such as the IrOx-BDD system described, requires ultra-pure, customizable diamond materials. 6CCVD is uniquely positioned to supply the foundational materials and advanced processing required to replicate and scale this research.

Applicable Materials

To achieve the electrochemical stability and high conductivity necessary for IrOx deposition and CO₂RR, the following 6CCVD materials are recommended:

Heavy Boron Doped Polycrystalline Diamond (BDD-PCD): Ideal for large-scale applications and high current density cells. We offer BDD-PCD wafers/plates up to 125mm diameter, ensuring the wide potential window and robustness required for complex chemical environments (like the acidic Ir precursor solution).
Highly Polished Boron Doped Single Crystal Diamond (BDD-SCD): Recommended for fundamental research requiring highly uniform, low-defect surfaces (Ra < 1nm). Available in thicknesses from 0.1µm up to 500µm.

Customization Potential for Research Replication

The paper utilizes BDD as a stable electrode platform. 6CCVD offers the critical customization services needed to advance this electrochemical research:

Requirement/Capability	6CCVD Offering	Benefit to Researcher
Custom Dimensions	Plates/wafers up to 125mm (PCD) and custom laser cutting.	Enables scale-up of CO₂RR cells and fabrication of specific electrode geometries.
BDD Doping Control	Fine control over Boron concentration to optimize conductivity (Ω-cm).	Allows researchers to precisely tune conductivity for maximized current generation and reduced ohmic drop.
Metalization Services	In-house deposition of Au, Pt, Pd, Ti, W, and Cu contact layers.	Provides robust, low-resistance ohmic contacts essential for reliable electrochemical characterization and high-throughput testing.
Surface Finish	Standard polishing for PCD (Ra < 5nm) and optical grade polishing for SCD (Ra < 1nm).	Minimizes surface defects, ensuring maximal electrochemical stability and consistent catalytic deposition kinetics.

Engineering Support

The successful modification of diamond surfaces for electrocatalysis, like this IrOx-BDD work, is a specialized field. 6CCVD’s in-house PhD team specializes in CVD diamond characteristics and processing. We offer consultation services to assist researchers with:

Optimizing BDD material selection (SCD vs. PCD, doping level) for similar CO₂ Electroreduction (CO₂RR) projects.
Designing appropriate metal contact pads (e.g., Ti/Pt/Au) compatible with aggressive electrochemical environments.
Determining optimal thickness and surface preparation for highly sensitive analytical applications.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We handle global shipping (DDU default, DDP available) to ensure your critical materials arrive quickly and safely.

View Original Abstract

Electroreduction of carbon dioxide (CO2) at iridium oxide-modified boron-doped diamond (IrOx-BDD) electrodes in aqueous electrolytes was studied by voltammetric method. The aim of this study was to find out the catalytic effect of IrOx to produce fine chemicals contained of two or more carbon atoms (for example acetic acid) in high percentage. Characterization using FE-SEM and XPS indicated that IrO2 can be deposited at BDD electrode, whereas characterization using cyclic voltammetry indicated that the electrode was applicable to be used as working electrode for CO2 electroreduction.

Tech Support

Original Source

DOI: https://doi.org/10.1088/1757-899x/188/1/012030