Boron-doped Diamond Electrode Research Articles

Treatment of cattle slaughterhouse wastewater by sequential coagulation-flocculation/electrooxidation process

The objective of this study was to assess the efficiency of electrochemical treatment after pre-treatment coagulation-flocculation (CF) in removing chemical oxygen demand (COD) and turbidity from slaughterhouse wastewater (SWW). During the pre-treatment, FeCl3 showed superior efficacy compared to the other coagulant, effectively eliminating 50% of the COD and 68% of the turbidity. Due to the insufficient removal efficiencies of COD and turbidity, a secondary treatment was required. The coagulated effluent was then treated in a continuous electrooxidation reactor (CEO) using a boron-doped diamond (BDD) electrode. The objective was to examine the impact of current density (5 to 30 mA/cm2), wastewater flow rate (0.9 to 3.6 L/hour), and supporting electrolyte concentration (1 to 3 g/L NaCl). The CEO reactor had higher removal efficiency for COD (97%) and turbidity (~100%) when operated under the optimum treatment conditions (j = 30 mA/cm2, Q = 0.9 L/h, pH = 8.5, SE = 3.0 g/L NaCl, and hydraulic retention time (HRT) = 1 hour). At these optimum conditions, the total operating cost (OC) was 3.5 US $/m3 (1.5 US $/kgCOD). The findings demonstrated that the CF + CEO reactor proved to be a very efficient alternate method for the treatment the SWW.

An innovative approach for selective and robust screening of NBOHs, NBOMes, and LSD in forensic samples using a 3D-Printed electrochemical double cell

Lysergic acid diethylamide (LSD) and two phenethylamine classes (NBOHs and NBOMes) are the main illicit drugs found in seized blotter papers. The preliminary identification of these substances is of great interest for forensic analysis. In this context, this work constitutes the inaugural demonstration of an efficient methodology for the selective detection of LSD, NBOHs, and NBOMes, utilizing a fully 3D-printed electrochemical double cell (3D-EDC). This novel 3D-EDC enables the use of two working electrodes and/or two supporting electrolytes (at different pHs) in the same detection system, with the possibility of shared or individual auxiliary and pseudo-reference electrodes. Thus, the selective voltammetric detection of these substances is proposed using two elegant strategies: (i) utilizing the same 3D-EDC platform with two working electrodes (boron-doped diamond (BDD) and 3D-printed graphite), and (ii) employing two pH levels (4.0 and 12.0) with 3D-printed graphite electrode. This comprehensive framework facilitates a fast, robust, and uncomplicated electrochemical analysis. Moreover, this configuration enables a rapid and sensitive detection of LSD, NBOHs, and NBOMes in seized samples, and can also provide quantitative analysis. The proposed method showed good stability of the electrochemical response with RSD <9 % for Ip and <5 % for Ep, evaluating all oxidation processes observed for studied analytes (n = 7) at two pH levels, using the same and different (n = 3) working electrodes. It demonstrates a broad linear range (20–100 and 20–70 μmol L−1) and a low LOD (1.0 μmol L−1) for quantification of a model molecule (LSD) at the two pHs studied. Hence, the 3D-EDC combined with voltammetric techniques using BDD and 3D-printed graphite electrodes on the same platform, or only with this last sensor at two pH values, provide a practical and robust avenue for preliminary identification of NBOHs, NBOMes, and LSD. This method embodies ease, swiftness, cost-efficiency, robustness, and selectivity as an on-site screening tool for forensic analysis.

Gallium Nitride Electrodeposition at Indium Tin Oxide and Fluorine Tin Oxide Electrodes in Ammonium Nitrate and Gallium Nitrate Aqueous Solution

Gallium nitride thin films in semiconductor technology have garnered interest. This study aims to develop an effective GaN electrodeposition technique applicable where needed. To determine the optimal conditions, cyclic voltammetry (CV) was done on a boron-doped diamond electrode at 0.01 mV/s potential scan rate and at 0.8 V vs. Ag/AgCl (Saturated KCl) constant applied potential. In the CV study, a well-defined peak formed at -1.75 V vs. Ag/Ag/Cl (Saturated KCl). To start examining thin film features on Indium Tin Oxide (ITO) and Fluorine Tin Oxide (FTO) electrodes, chronoamperometry (CA) measurements were done at time scales ranging from 3600s to 14,000s and at a constant applied potential of -1.7 V vs. Ag/AgCl (Saturated KCl). The characterization methods used to examine the samples included SEM and EDS. The optimal weight electrodeposition percentages of Ga and N on ITO were 10.3% and 27.2% and 47.3% and 12.7% on FTO respectively.

Electrochemical Detection of the Antidiabetic Medication Metformin in Human Urine and Pharmaceutical Tablets Using Boron-Doped Diamond Electrode

Electrochemical Detection of the Antidiabetic Medication Metformin in Human Urine and Pharmaceutical Tablets Using Boron-Doped Diamond Electrode

Determination of benzoylecgonine in synthetic urine samples via square-wave voltammetry with boron-doped diamond electrode

Determination of benzoylecgonine in synthetic urine samples via square-wave voltammetry with boron-doped diamond electrode

Electrocatalytic water treatment of per- and polyfluoroalkyl substances reduces adsorbable organofluorine and bioaccumulation potential.

Per- and polyfluoroalkyl substances (PFAS) are pervasive in industrial processes, eliciting public concern upon their release into municipal sewers or the environment. Removing PFAS from the environment has become an urgent need. However, because potential endpoints span from energy-intensive complete mineralization to partial PFAS transformation, understanding and developing metrics for evaluating PFAS treatment can be a challenge. The goal of this study was to evaluate and compare the effectiveness of electrocatalytic degradation of PFAS with boron-doped diamond (BDD) electrodes using four techniques: LC-MS/MS target analysis, fluoride ion (F-), adsorbable organofluorine (AOF), and bioaccumulation potential using lipid-bilayer partition (LBP) tests. After 3 hours of electrocatalysis, >99% perfluorooctanoic acid (PFOA) degradation was achieved and corresponded with 84% conversion to F-, which was substantial - though intentionally not complete - defluorination. For the same 3 hour treatment time, AOF and LBP coefficient were reduced by 95% and 83%, respectively. LBP's detection limit was 2 orders of magnitude higher than that of AOF, so the positive correlation observed between LBP and AOF (r = 0.86) suggests AOF's practical utility as a design metric for assessing bioaccumulation potential of various organofluorine transformation by-products.

Recent Trends in Therapeutic and Electroanalytical Applications of Boron-Doped Diamond Sensors

Abstract:: In recent years, research and development efforts have been heavily focused on conductive diamond electrodes for electrochemical applications. Such initiatives may have been spurred by their broad potential window, low background current, chemical inertness, and mechanical robustness. Compared to other carbon-based materials, conducting diamond can oxidize several analytes before the breakdown of water in aqueous electrolytes. Since the evolution of oxygen and hydrogen does not obstruct the analysis, this is significant for the detection and/or identification of species in solution. As a result, conductive diamond electrodes expand the application of electrochemical detection and make it possible to use them for analytes that are incompatible with traditional electrode materials. Fabricating boron-doped diamond films via chemical vapor deposition on different substrates is of special interest. This article highlights the therapeutic and electroanalytical applications of boron-doped diamond electrodes in various aspects in addition to the synthetic strategies to obtain Boron Doped Diamond Electrodes (BDDE), the cost-effectiveness of BDD and its in-vivo compatibility that will help the analytical researchers to learn almost everything about the previous studies done on BDDE and encourage them to work more efficiently in this research field.

Uranium electrodeposition at boron-doped diamond electrodes

Uranium electrodeposition at boron-doped diamond electrodes

Phosphate and Nitrate Electrochemical Sensor Based on a Bifunctional Boron-Doped Diamond Electrode.

Phosphorus and nitrogen are important elements in both environmental cycles and biological growth, and their imbalance can lead to serious environmental and biological problems. It is important to be able to monitor the concentration of nitrate and phosphate in the water online. In this paper, a bifunctional boron-doped diamond (BDD) electrode with repeatable electrochemical renewal and modification ability has been developed and used as a shared working electrode for the determination of nitrate and phosphate. First, phosphate can be detected directly with a bare BDD electrode. After a thin copper (Cu) layer was electrodeposited on the BDD electrode, nitrate could be determined. The copper layer is then removed under a positive voltage, and the BDD electrode is renewed and can be used again for phosphate detection. This method enables the detection of both phosphate and nitrate while also improving the stability and repeatability through the renewal of the electrode surface. The segmented linear ranges for phosphate were 0.02-0.4 and 0.4-3 mg/L with a detection limit of 0.004 mg/L. The sensor detected nitrate in a wide concentration range, with segmented linear relationships in the ranges of 0.07-3 and 3-100 mg/L, with a detection limit of 0.065 mg/L. The electrochemical sensor based on the BDD electrode has a good reproducibility for phosphate and nitrate detection. The relative standard deviation (RSD) values of the current responses were 2.98, 2.79, 1.66, 1.81, and 1.23%, respectively, for 35 consecutive tests in 0.05, 0.2, 0.5, 1, and 1.5 mg/L phosphate solution. The RSD values of the current responses were 2.00, 0.97, and 1.03%, respectively, for 25 consecutive tests in 5, 7, and 10 mg/L nitrate solution.

Nanostructured boron-doped diamond electrodes for two-electron water oxidation to produce hydrogen peroxide

Boron-doped diamond (BDD) electrodes have been widely used in water treatment, e.g., degradation of antibiotics and pigments for water purification. Hydrogen peroxide production by two-electron electrochemical oxidation of water is a green and attractive method that has the potential to replace the conventional anthraquinone autoxidation (AO) process. In this study, BDD films were prepared on single-crystal silicon wafers by using hot-filament chemical vapor deposition (HFCVD) technique. Then, dense tubular nanostructure (nanotubes) arrays were prepared on the BDD films employing inductively coupled plasma (ICP) etching. Energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) proved the formation of oxygen-terminated nanostructures, which was ascribed to the oxygen plasma and the self-masking. The length of diamond nanotubes as well as the root diameter increased gradually and non-linearly with the increase of etching time. It was indicated by cyclic voltammetry (CV) analysis that the effective active area of the electrodes increased after etching, and variations of resulting reaction performance were observed. The oxygen-terminated and nanostructured BDD electrode obtained by etching with the optimized parameters features better electrocatalytic performance, with reduced oxidation potential and 46.8 % higher Faraday Efficiency (FE) for hydrogen peroxide production, compared to the original BDD sample. Therefore, the manufacturing of nanostructures is an effective method to improve the efficiency of BDD water oxidation for the production of hydrogen peroxide.

Biofouling and performance of boron-doped diamond electrodes for detection of dopamine and serotonin in neuron cultivation media

Boron doped diamond has been considered as a fouling-resistive electrode material for in vitro and in vivo detection of neurotransmitters. In this study, its performance in electrochemical detection of dopamine and serotonin in neuron cultivation media Neurobasal™ before and after cultivation of rat neurons was investigated. For differential pulse voltammetry the limits of detection in neat Neurobasal™ medium of 2 µM and 0.2 µM for dopamine and serotonin, respectively, were achieved on the polished surface, which is comparable with physiological values. On oxidized surface twofold higher values, but increased repeatabilities of the signals were obtained. However, in Neurobasal™ media with peptides-containing supplements necessary for cell cultivation, the voltammograms were notably worse shaped due to biofouling, especially in the medium isolated after neuron growth. In these complex media, the amperometric detection mode at +0.75 V (vs. Ag/AgCl) allowed to detect portion-wise additions of dopamine and serotonin (as low as 1–2 µM), mimicking neurotransmitter release from vesicles despite the lower sensitivity in comparison with neat NeurobasalTM. The results indicate substantial differences in detection on boron doped diamond electrode in the presence and absence of proteins, and the necessity of studies in real media for successful implementation to neuron-electrode interfaces.

Development of an environmentally friendly method for the determination of prednisolone in natural waters using unmodified boron-doped diamond electrode

Development of an environmentally friendly method for the determination of prednisolone in natural waters using unmodified boron-doped diamond electrode

PFAS degradation by anodic electrooxidation: Influence of BDD electrode configuration and presence of dissolved organic matter

Per- and poly-fluoroalkyl substances (PFAS) pose substantial environmental and human health risks. Electrochemical oxidation technology is a promising large-scale solution for PFAS degradation due to its simplicity and minimal waste generation. This study investigated the electrochemical performance of boron-doped diamond (BDD) electrodes in degrading PFAS using a recirculation cell with plate and mesh electrodes. The study found that increasing the current density from 6.4 mA/cm2 to 40 mA/cm2 resulted in a transition of the reaction rate from pseudo-first-order toward zero-order kinetics. The stepwise degradation mechanism and the formation of intermediate products were also explored. Carbon and fluorine molar balance analysis revealed that the missing intermediates do not contain fluoride atoms in their molecular formula. The shape and surface of the electrodes had a significant impact on their performance, in particular, improving the degradation of the most recalcitrant perfluorobutanoic acid. The influence of different fractions of dissolved organic matter (DOM) on perfluorohexanoic acid degradation shows that overall, DOM does not significantly inhibit its degradation. Some inhibition was observed in the presence of DOM enriched in carbohydrates, organics that are known to exert strong interaction properties with organic and inorganic surfaces. The synergistic effect of direct anodic oxidation and indirect degradation by reactive radical species enables the decomposition of both DOM and PFAS. Finally, high removal percentages of short (up to 96 %) and long-chain PFAS (up to 99 %) were obtained using BDD electrooxidation cells combining plate and mesh electrodes when treating reverse osmosis concentrate containing PFAS.

Highly sensitive and selective electrochemical monitoring of nickel in crude oil samples using cathodically pretreated-boron doped diamond electrode

Crude oil is a mixture of hydrocarbons found underground in liquid form and is a valuable fuel with a complex chemical structure. Crude oil is known to come from decaying plants and animals as a fossil product that emerged from the anaerobic process millions of years ago. In the formation of oil, it is accepted that crude oil has an organic origin, and most of the crude oil is found in sedimentary rocks, and the sediments have an organic and inorganic content.In this study, a voltammetric method was developed for the analysis of nickel, one of the metals with the highest density as a heavy metal in crude oil. In the developed voltammetric method, the boron-doped diamond electrode was activated in the cathodic direction at −3.0 V in 0.5 M H2SO4 media.As a result of this cathodic activation, nickel gave a very sensitive anodic signal around −0.15 V on the electrode surface. This anodic signal was determined to be linear in the range of 0.05–0.6 μM around −0.15 V in BR (pH 3.0) media by the anodic stripping voltammetry method. The limit of detection and the limit of quantification were determined to be 0.003 μM and 0.01 μM, respectively. The proposed method allowed the selective analysis of nickel in the crude oil sample without any separation and enrichment process.

Nitrate Sensor with a Wide Detection Range and High Stability Based on a Cu-Modified Boron-Doped Diamond Electrode.

This paper describes an electrochemical sensor based on a Cu-modified boron-doped diamond (BDD) electrode for the detection of nitrate-contaminated water. The sensor utilizes the catalytic effect of copper on nitrate and the stability of the BDD electrode. By optimizing the electrolyte system, the linear detection range was expanded, allowing the sensor to detect highly concentrated nitrate samples up to 100 mg/L with a low detection limit of 0.065 mg/L. Additionally, the stability of the sensor was improved. The relative standard deviation of the current responses during 25 consecutive tests was only 1.03%. The wide detection range and high stability of the sensor makes it suitable for field applications and the on-site monitoring of nitrate-contaminated waters.

Selective recovery of lithium from spent LiFePO4 powders with electrochemical method

In recent years, with the flourishing of new energy vehicles, the lithium iron phosphate (LFP) batteries are vigorously developed due to their low cost and high stability. Meanwhile, it leads to an increase in large-scale retirement of batteries. Therefore, it is crucial to develop a green and efficient recycling method. In this work, an indirect electrochemical oxidation has been proposed for selective leaching of Li ions. An electrochemical system using boron-doped diamond electrode (BDD) with high oxygen evolution potential as anode and RuO2/Ti as cathode has been built to generate oxidizing species and enhance the oxidative reaction contact for an indirect oxidation of LFP. The operating conditions were optimized to a current density of 110 mA/cm2, Na2SO4 electrolyte concentration of 0.225 M, pH of 1.7, solid–liquid ratio of 16 g/L. The leaching efficiency of Li ions reached up to 95.53 % and the leaching efficiency of Fe ions was less than 0.01 % at room temperature. A purity of lithium carbonate product of 99.93 % was obtained after precipitation of the leaching solution. This proposed method could realize efficient and rapid selective leaching of Li and Fe ions by indirect oxidation, realizing selective leaching and significantly reducing the usage of acid.

A novel synthetic strategy of mesoporous Ti4O7-coated electrode for highly efficient wastewater treatment

Suboxidized titanium, as a promising anode for electrocatalytic oxidation reactions in wastewater treatment, presents a viable pathway to solve the challenging water pollution. However, current suboxidized titanium anodes are primarily fabricated hot pressing of by suboxidized titanium powders, further hampering their application in wastewater treatment due to high costs and complex shaping processes. To overcome these limitations, this work employs the plasma electrolytic oxidation (PEO) technology to in-situ fabricate porous TiO2 coating precursors on commercial pure titanium substrates, followed by an annealing process to carefully reduce the TiO2 coatings with hydrogen gas, and finally achieving the cost-effective production of high-purity Magnéli phase Ti4O7-coated electrode. The obtained Ti4O7-coated electrodes exhibit a highly ordered granular structure, good crystallinity, wide electrochemical window, and low interfacial charge transfer resistance. Importantly, the Ti4O7-coated electrodes also offer a simple fabrication process, lower energy consumption, and reduced costs compared to advanced boron-doped diamond (BDD) and bulk Ti4O7 electrode. The electrochemical oxidation tests also demonstrate that Ti4O7-coated electrodes can achieve the complete degradation of 100 mg/L phenol within 240 minutes, exhibiting excellent catalytic activity and potential applications in wastewater treatment.

Quantification of caffeine in coffee cans using electrochemical measurements, machine learning, and boron-doped diamond electrodes.

Electrochemical measurements, which exhibit high accuracy and sensitivity under low contamination, controlled electrolyte concentration, and pH conditions, have been used in determining various compounds. The electrochemical quantification capability decreases with an increase in the complexity of the measurement object. Therefore, solvent pretreatment and electrolyte addition are crucial in performing electrochemical measurements of specific compounds directly from beverages owing to the poor measurement quality caused by unspecified noise signals from foreign substances and unstable electrolyte concentrations. To prevent such signal disturbances from affecting quantitative analysis, spectral data of voltage-current values from electrochemical measurements must be used for principal component analysis (PCA). Moreover, this method enables highly accurate quantification even though numerical data alone are challenging to analyze. This study utilized boron-doped diamond (BDD) single-chip electrochemical detection to quantify caffeine content in commercial beverages without dilution. By applying PCA, we integrated electrochemical signals with known caffeine contents and subsequently utilized principal component regression to predict the caffeine content in unknown beverages. Consequently, we addressed existing research problems, such as the high quantification cost and the long measurement time required to obtain results after quantification. The average prediction accuracy was 93.8% compared to the actual content values. Electrochemical measurements are helpful in medical care and indirectly support our lives.

Design, Validation, and Fabrication of a Tailored Electrochemical Reactor Using 3D Printing for Studies of Commercial Boron-Doped Diamond Electrodes.

Boron-doped diamond (BDD) electrodes are the most effective and resistant electrodic materials to perform advanced oxidation processes. Having a reactor that can provide adequate hydrodynamic conditions is mandatory to use these electrodes effectively. In this work, the diamond anode electrochemical reactor (E3L-DAER) is designed to fulfill this necessity. Several features are included to improve its efficiency, like conic inlet/outlet, flow enhancers, and a reduced interelectrode gap. The fluid dynamic validation has been performed using computer fluid dynamics (CFD) calculations, residence time distribution (RDT) curves, and mass transfer analysis. The reactor has been made using a three-dimensional (3D) printing stereolithography (SLA) technique, which allows us to build chemical-resistant reactors with nonstandard and tailored features in a cheap and fast way. The obtained results demonstrate that the designed reactor has the required fluid dynamics properties to perform reliable BDD electrode studies and applications. Finally, a BDD electrode was used to test the production of different oxidants such as persulfate, peroxophosphate, and chlorine-derived species.

Simultaneous voltammetric detection of benzene, naphthalene and anthracene from water using boron-doped diamond electrode

In this study, a simple, fast and sensitive voltammetric detection using boron-doped diamond (BDD) electrode was proposed for simultaneous quantification of benzene (BZ), naphthalene (NF) and anthracene (AC) from priority organic pollutants class in real tap water. The electrochemical behaviors of individual and simultaneous BZ, NF and AC studied by cyclic voltammetry (CV) on BDD electrode showed a large separation between their oxidation potential, which allowed the development of simple simultaneous detection method. Differential-pulse voltammetry (DPV) technique operated at step potential of 5 mV and modulation amplitude of 200 mV enabled to reach the lowest limits of detection of 0.40 μM for BZ, 0.04 μM for NF and 0.70 nM for AC, which is appropriate for water quality control related to their environmental quality standards. No significant influence of chloride ions was found and the method was validated in real tap water and surface water spiked with known concentrations of BZ, NF and AC, which proved the practical utility of the method for water quality control.