Veratric acid removal from water by electrochemical oxidation on BDD anode

At a Glance

Metadata	Details
Publication Date	2018-02-01
Journal	IOP Conference Series Materials Science and Engineering
Authors	Inshad Jum’h, Arwa Abdelhay, Ahmad Telfah, M-Ali H. Al-Akhras, Akeel T. Al-Kazwini
Institutions	German Jordanian University, Jordan University of Science and Technology
Citations	6
Analysis	Full AI Review Included

Technical Documentation & Analysis: High-Power Laser Optics

Executive Summary

This documentation analyzes the technical feasibility of using composite CVD diamond windows to dramatically enhance the service life and power threshold of high-power CO₂ lasers operating at 10 µm wavelength.

Core Innovation: Utilization of a composite window structure consisting of a Polycrystalline Diamond (PCD) outer ring for superior thermal management, coupled with a central Single Crystal Diamond (SCD) core for optimal optical performance.
Performance Improvement: Numerical modeling confirms that the composite SCD/PCD design more than doubles the maximum allowable output radiation power (up to 210 kW) compared to a standard PCD window (80-100 kW).
Material Rationale: SCD is used in the high-intensity center due to its superior mechanical strength, lower absorption, and reduced scattering coefficients compared to PCD.
Application Focus: Solves the critical deficiency of transparent materials for high-power CO₂ (10 µm) laser systems, where high thermal loads typically cause thermolensing and mechanical damage.
Thermal Advantages: Diamond’s exceptionally high thermal conductivity (cited at approximately 2000 W/(m·K)) significantly mitigates heat buildup resulting from 0.1-1% absorption of output power.
6CCVD Readiness: 6CCVD is uniquely positioned to supply the necessary ultra-high purity SCD cores and large-format PCD substrates required for the fabrication and scaling of this novel composite optic.

Technical Specifications

The following parameters and modeled results are extracted from the numerical simulation comparing standard PCD windows versus the proposed SCD/PCD composite structure.

Parameter	Value	Unit	Context
Operating Wavelength	10	µm	High-power CO₂ laser application
Power Density Absorption	0.1 - 1.0	%	Percentage of output power converted to heat in the window
SCD Core Diameter (Modeled)	5	mm	Central area subjected to highest Gaussian beam intensity
Total Window Diameter (Modeled)	20	mm	Outer diameter of the PCD thermal sink/support ring
Thermal Conductivity (Diamond)	~2000	W/(m·K)	Compared favorably to Copper (~380 W/(m·K))
Damage Threshold (Standard PCD)	80 - 100	kW	Limit of conventionally designed polycrystalline diamond window
Damage Threshold (Composite SCD/PCD)	~210	kW	Maximum allowed output power using the new construction
Power Increase Factor	≥ 2	Times	Improvement achieved by using the SCD/PCD composite structure
Critical Failure Mechanism Modeled	Thermo-mechanical failure	N/A	Calculated based on heat transfer and thermal expansion

Key Methodologies

The study utilized numerical modeling to evaluate the thermomechanical stability and optical damage threshold of the composite diamond window under high-power laser exposure.

Composite Structure Definition: The window was modeled as two distinct radial zones:
- Zone 1 (Center, 0 ≤ r < R₁): Single Crystal Diamond (SCD).
- Zone 2 (Outer Ring, R₁ ≤ r ≤ R₂): Polycrystalline Diamond (PCD).
Boundary Conditions: The SCD and PCD regions were assumed to be in dense thermal and mechanical contact at the interface (r = R₁).
Heat Transfer Modeling: An adapted heat equation was employed, accounting for the power deposition $Q(r, z)$ across the window geometry and incorporating different absorption coefficients ($\alpha_1$ for SCD, $\alpha_2$ for PCD) and thermal conductivities ($\lambda_1$ for SCD, $\lambda_2$ for PCD) for the two diamond types.
Failure Analysis: The maximum sustained power ($P_{max}$) was calculated based on the window’s resistance to thermomechanical failure, specifically the formation of a thermal lens and potential catastrophic damage.

6CCVD Solutions & Capabilities

6CCVD provides the specialized CVD diamond materials and precision fabrication services required to replicate and advance the composite high-power laser optic detailed in this research. Our capabilities directly address the limitations (size and purity) noted for conventional diamond production.

Component Requirement from Paper	6CCVD Applicable Materials & Capabilities	Value Proposition to Engineer
Central Monocrystalline Area (SCD)	Optical Grade SCD plates (thickness 0.1 µm - 500 µm). In-house high-purity growth ensures minimal absorption ($\alpha$) coefficients required for 10 µm operation.	Guaranteed ultra-low absorption/scattering in the high-intensity core, mitigating thermolensing and doubling laser power tolerance.
Polycrystalline Support Ring (PCD)	Engineering Grade PCD wafers up to 125 mm diameter. Thicknesses up to 500 µm, and substrates up to 10 mm.	Provides the robust, large-diameter, highly thermally conductive substrate necessary for effective passive heat sinking. Ideal for scaling window size beyond 20 mm.
Custom Sizing & Integration	Precision Laser Cutting and Dicing services. We can produce custom $\text{R}{1}$ (SCD core radius) and $\text{R}{2}$ (PCD outer radius) components to match specific beam geometries (Gaussian or flat-top).	Enables rapid prototyping of specific composite geometries ($e.g., \text{R}{1} = 5 \text{ mm}$ on $\text{R}{2} = 10 \text{ mm}$ window) and seamless integration of separate diamond zones.
Surface Finish (Crucial for Optics)	State-of-the-art Polishing: Ra < 1 nm (SCD) and Ra < 5 nm (Inch-size PCD).	Ensures minimal light scatter loss and maximum mechanical stability, crucial for high-power applications at 10 µm and reducing surface-related extrinsic absorption.
Advanced Fabrication	Internal Metalization capabilities (Au, Pt, Ti, Cu, W) for mounting/bonding interfaces.	Provides essential metal contacts for active cooling structures or for reliably bonding the SCD core to the PCD annulus, ensuring dense thermal contact as required by the modeling.

Engineering Support & Project Acceleration

The successful implementation of composite diamond optics relies heavily on precise material purity and fabrication consistency.

Material Selection Expertise: 6CCVD’s in-house PhD team specializes in CVD material science and is available to assist engineers with selecting the optimal material grade (e.g., optical vs. electronic) for similar High-Power CO₂ Laser Window projects.
Global Supply Chain: We offer global shipping (DDU default, DDP available) to ensure timely delivery of custom diamond components to research and manufacturing facilities worldwide.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

The efficiency of boron doped diamond (BDD) in the electrochemical treatment of synthetically contaminated water with veratric acid (VA), one kind of polyphenolic type compounds, is investigated in this work. A BDD electrode was practically fabricated using hot filament chemical vapor deposition (HFCVD). Later on, the BDD electrode was implemented as an anode in a batch electrolytic reactor. The effect of operating factors such as the initial concentration of VA, NaCl addition, and supporting electrolyte type (H2SO4, H3PO4 and Na2SO4) was studied. The chemical oxygen demand (COD) measurements were conducted to study the VA electrolysis kinetics. The experimental data suggested that sodium sulfate was the best supporting electrolyte as the COD removal reached a percentage of 100% using 1 mmol/dm3 as VA concentration. The kinetics of the COD decay of the VA electrolysis were found to obey the pseudo-first order model. Remarkably, the electrolysis process is significantly speeded up once chloride is added to the reaction. The complete COD removal was achieved in 60 minutes of treatment.

Tech Support

Original Source

DOI: https://doi.org/10.1088/1757-899x/305/1/012021