Correction - Vertically aligned boron-doped diamond nanostructures as highly efficient electrodes for electrochemical supercapacitors

At a Glance

Metadata	Details
Publication Date	2024-01-01
Journal	Journal of Materials Chemistry A
Authors	Shradha Suman, Dhananjay K. Sharma, Ondrej Szabó, Benadict Rakesh, Marián Marton
Institutions	Academy of Scientific and Innovative Research, Czech Academy of Sciences, Institute of Physics
Citations	2
Analysis	Full AI Review Included

Executive Summary

This correction details the precise fabrication methodology for vertically aligned Boron-Doped Diamond (BDD) nanostructures, designed to serve as highly efficient electrodes for electrochemical supercapacitors.

Core Material System: Boron-Doped Diamond (BDD) films (BMCDp and BUNCDp) grown on alumina (Al₂O₃) substrates using Linear Antenna Microwave Plasma Enhanced Chemical Vapor Deposition (LA MW CVD).
Precursor Strategy: Trimethyl borate (TMBT) was utilized as the combined source for carbon, boron, and oxygen, enabling high boron incorporation.
High Doping Levels: The growth process achieved extremely high B/C ratios, specifically 312,500 ppm and 328,000 ppm, critical for enhancing diamond conductivity.
Nanostructure Fabrication: Vertically aligned structures were created using a self-organized masking technique involving an 8 nm Au layer, which formed nano-droplets upon H₂ plasma heat treatment (500 °C).
Pattern Transfer: Reactive Ion Etching (RIE) using an O₂/CF₄ plasma mixture was employed to transfer the Au nanodroplet pattern into the BDD film, creating the desired high surface area nanostructures.
Application Focus: The resulting BDD nanostructures are optimized for use as electrodes, leveraging diamond’s stability and conductivity for high-performance electrochemical supercapacitors.

Technical Specifications

Parameter	Value	Unit	Context
CVD Reactor Type	LA MW CVD	N/A	SCIA cube 300 system
Substrate Material	Al₂O₃	N/A	Alumina
Nucleation Size	5	nm	Nanodiamond powder suspension
Substrate Annealing Temp	1000	°C	1 h in air (pre-CVD preparation)
BDD Growth Temperature	600	°C	Maintained during 30 h growth
BDD Growth Pressure	30	Pa	CVD chamber pressure
Carbon/Boron Source	TMBT	N/A	Trimethyl borate
CO₂/H₂ Ratio	0.2	%	Gas mixture composition
B/C Ratio (BMCDp)	312,500	ppm	1% TMBT flow rate
B/C Ratio (BUNCDp)	328,000	ppm	4% TMBT flow rate
Au Mask Thickness	8	nm	Initial deposited layer for masking
Mask Heat Treatment	500	°C	10 min in H₂-based microwave plasma
RIE System	Phantom III	N/A	Capacitive Coupled Plasma (Trion Technology)
RIE Gas Flow (O₂/CF₄)	60/3	sccm	5% CF₄ concentration
RIE Pressure	150	mTorr	Etching process pressure
RIE RF Power	150	W	Applied power during etching
RIE Etching Time	6	min	Duration of nanostructure fabrication
Au Mask Removal Etchant	HNO₃ : HCl	1:3 (n/n)	Standard wet chemical etching

Key Methodologies

The fabrication of the vertically aligned BDD nanostructures involved a multi-step process combining advanced CVD growth with plasma etching techniques:

Substrate Preparation: Alumina (Al₂O₃) substrates were cleaned (NH₄OH/H₂O₂ solution), rinsed, and annealed at 1000 °C for 1 hour in air.
Nucleation: Substrates were ultrasonically nucleated using a suspension of 5 nm nanodiamond powder in deionized water.
BDD Film Growth (LA MW CVD):
- Growth was performed for 30 hours at 600 °C and 30 Pa pressure.
- Gas mixture: H₂/TMBT/CO₂ (CO₂/H₂ ratio of 0.2%).
- Doping control was achieved by varying TMBT flow rate (1% for BMCDp, 4% for BUNCDp), resulting in B/C ratios exceeding 312,500 ppm.
Au Mask Deposition: An 8 nm thick Au layer was deposited onto the pristine BDD films (BMCDp and BUNCDp).
Self-Organized Mask Formation: The Au-coated films were heat treated in an H₂-based microwave plasma at 500 °C for 10 minutes, causing the Au layer to self-organize into an array of nano-droplets.
Nanostructure Etching (RIE):
- The Au-masked films were etched using a capacitive coupled plasma system (Phantom III).
- Etching gas: O₂/CF₄ mixture (60/3 sccm flow, 5% CF₄).
- Process parameters: 150 mTorr pressure and 150 W RF power for 6 minutes.
Mask Removal: The remaining Au nanodroplets were removed using a standard wet chemical etch (HNO₃ : HCl at 1:3 volume ratio).

Commercial Applications

Boron-Doped Diamond (BDD) electrodes, particularly in nanostructured, vertically aligned configurations, are highly valued in applications requiring extreme chemical stability, wide electrochemical windows, and high surface area for charge storage.

Advanced Energy Storage:
- Supercapacitors/Hybrid Devices: Utilizing the high surface area and excellent conductivity of BDD nanostructures to achieve high power density and long cycle life, suitable for regenerative braking systems and uninterruptible power supplies (UPS).
- High-Temperature/Harsh Environment Batteries: BDD’s stability allows operation in conditions where conventional carbon electrodes fail.
Industrial Electrochemistry:
- Wastewater Treatment: BDD electrodes are highly effective for advanced oxidation processes (AOPs) due to their ability to generate powerful hydroxyl radicals, enabling the destruction of persistent organic pollutants (POPs).
- Electrochemical Synthesis: Used in the production of ozone, hydrogen peroxide, and other high-value chemicals requiring high overpotentials.
Sensing and Detection:
- Biosensors and Chemical Sensors: The inertness and low background current of BDD make it ideal for highly sensitive electrochemical detection in biological and corrosive media.
Micro/Nano-Electronics:
- High-Frequency Devices: BDD’s excellent thermal conductivity and electronic properties make it suitable for heat dissipation and active components in high-power radio frequency (RF) electronics.

View Original Abstract

Correction for ‘Vertically aligned boron-doped diamond nanostructures as highly efficient electrodes for electrochemical supercapacitors’ by Shradha Suman et al. , J. Mater. Chem. A , 2024, https://doi.org/10.1039/D3TA07728D.

Tech Support

Original Source

DOI: https://doi.org/10.1039/d4ta90146k