Cyclic Voltammetry Methods Research Articles

A reusable Behavior of Ruthenium Oxide-PtNP-Nafion Metal Nano Composite Towards Glucose Biosensing

This study introduces a novel composite (RuO2-PtNP-N) for non-enzymatic glucose sensing. RuO2-PtNP-N is fabricated through electrodeposition of platinum nanoparticles onto a pre-cast RuO2-Nafion composite on a glassy carbon electrode. The research demonstrates that RuO2-PtNP-N exhibits superior sensitivity compared to RuO2-N and Pt-N composites. This enhanced performance is attributed to the favorable orientation of PtNPs within the porous RuO2 matrix. Various characterization techniques, including cyclic voltammetry, chronoamperometry, and spectroscopic methods, were employed to analyze the sensor’s electrochemical properties and surface characteristics. The RuO2-PtNP-N sensor displayed a linear response up to 24 mM glucose with a sensitivity of 0.328 mA mM-1 cm-2. Furthermore, the sensor exhibited good reproducibility over a 41-day period, indicating excellent surface stability. Additionally, the sensor demonstrated high selectivity for glucose in the presence of potential interfering species. The determination of glucose in serum samples highlights the sensor’s promising potential for practical applications

Influence of layered conductive coatings on electrochemical characteristics of NaFe(SO4)2cathode material

Rising production and consumption, and the high cost of lithium salts increased the price of lithium-ion batteries. Sodium-ion batteries are a promising replacement as safer and cheaper. However, the cathode materials for these batteries have low conductivity, which critically reduces their capacity. Modification with conductive additives is one way to solve this problem. Since a large electronic contact area of the active material with the conductive coating is required, the main candidates for such additives are materials with a layered structure. The purpose. To study the influence of layered conductive additives on the performance and kinetic parameters of eldfellite-structured cathode material. Methodology. By cyclic voltammetry and galvanostatic methods, it is found that as the 2D material additive concentration increases, the active material’s performance characteristics initially increase and then decrease, which is related to the sodium ions diffusion rate through the coating layer. Results and discussion. As a result of the modification effect evaluation of NaFe(SO4)2 cathode material with eldfellite structure by layered conductive coatings: graphite, molybdenum disulfide and MXene (Ti3C2Tx), it was determined that for each material there is a certain optimal concentration at which peak currents, capacitance and diffusion coefficient are maximized and resistance is minimized. The optimum additive quantities are 0.5% for MoS2 and MXene, and 0.2% for graphite. Conclusion. The influence of the concentration of 2D conductive coatings on the electrochemical properties of NaFe(SO4)2 intercalation material is shown.

Sensitivity of chitosan/reduced graphene oxide/manganese dioxide modified electrodes for cholesterol detection using cyclic voltammetry

Cholesterol detection needs to be carried out to detect early symptoms of dangerous diseases such as heart disease. The process of detecting cholesterol in the human blood requires a sensitive detection tool in order to produce accurate values. This paper reports the performance of chitosan thin films modified with reduced graphene oxide (rGO) and manganese dioxide (MnO2) as the sensitive layer of working electrodes in detecting cholesterol. The electrode substrate is a copper-screen printed electrode (copper-SPE) which was patterned into 5 mm of sensitive area. The chitosan and chitosan-reduced graphene oxide (rGO) matrices were deposited on the top of working electrodes. The characterization of chitosan, chitosan/rGO, and chitosan/rGO/MnO2 thin films was performed using AFM, FE-SEM, and FTIR. The electrochemical sensing properties of modified working electrode were observed using an electrochemical method of cyclic voltammetry (CV). The novelty of this research is the utilization of chitosan/rGO/MnO2 thin film-based working electrode for detecting cholesterol. The testing results indicated that the sensitivity of the modified working electrodes increased when working electrodes based on chitosan/rGO/MnO2 thin film were used for cholesterol detection compared to the working electrodes based on the chitosan thin film. It was proven from the sensitivity of working electrodes based on chitosan/rGO/MnO2 thin film which gave the lowest value of 3.21 × 10−5 µA/µM as well as the ability of working electrodes based on chitosan/rGO/MnO2 thin film which worked at limit of detection (LoD) 0.26 µM/L and limit of quantification (LoQ) 0.87 µM/L. Based on the sensitivity, LoD, and LoQ values, the chitosan/rGO/MnO2 modified electrodes can be used as working electrodes to measure cholesterol concentration in blood.

Green synthesis of natural gomutra and honey doped CeO[formula omitted] nanocomposite for green sensor, cyclic voltammetry, photocatalysis and antioxidant studies

The current study demonstrates, synthesis of cow urine and honey doped/CeO2 nanocomposite using simple reflux method and inexpensive process. The nanocomposite was characterized and confirmed by X-ray Diffractometer (XRD), Infrared Spectroscopy (IR), Scanning Electron Microscopy (SEM), TEM, Energy Dispersive X-ray spectroscopy (EDS), XPS, and UV–Visible (UV–Vis) spectroscopy techniques. The photocatalysis of methyl orange (MO) dye examined and degraded up to 92% and 93% using both cow urine and honey doped/CeO2 nanocomposite. Electrochemical reversibility (E0-ER), proton diffusion coefficient (D) was analyzed using 3M KCl electrolyte by cyclic voltammetry method (CV). The electrochemical sensor detection of tartaric acid and L-aspartic acid was assessed on developed material. The detection limits for tartaric acid were determined to be 2.09 μM and 3.58 μM, while for L-aspartic acid were 3.49 μM and 3.29 μM, respectively. Cow urine/CeO2 and honey/CeO2 had free radical scavenging activities of approximately 71.91 and 63.95%, respectively.

Fabrication and Characterization of High-Capacity Manganese Oxide Based Supercapacitor Electrode

Considerable attention has been directed towards the development of manganese oxide materials capable of simultaneously offering ample surface area and facilitating charge movement to enhance capacitance performance. In this study, oval-shaped manganese oxide (OS-MO) was synthesized via a straightforward hydrothermal method, followed by comprehensive characterization using various microscopic and spectroscopic techniques. The electrochemical supercapacitive performance of the resulting OS-MO-based electrode was evaluated in a three-electrode assembly workstation employing cyclic voltammetry and galvanostatic charge-discharge methods. The experimental findings revealed that OS-MO achieved an impressive specific capacitance of 629.62 Fg-1. Furthermore, the cyclic stability of OS-MO remained consistently high at approximately 89% over 1000 cycles at a fixed current density. These results suggest that the superior performance and stability of OS-MO can be attributed to its porous nature and high surface area. Consequently, OS-MO emerges as a promising candidate for applications in energy storage systems.

Insights into the Origins of Solar‐Assisted Electrochemical Water Oxidation in Allotropic Co5.47N/CoN Heterojunctions

Solar irradiation can efficiently promote the kinetics of the oxygen evolution reaction (OER) during water splitting, where heterojunction catalysts exhibit excellent photoresponsive properties. However, insights into the origins of photoassisted OER catalysis remain unclear, especially the interfaced promotion under convergent solar irradiation (CSI). Herein, novel allotropic Co5.47N/CoN heterojunctions were synthesized, and corresponding OER mechanisms under CSI were comprehensively uncovered from physical and chemical aspects using the in situ Raman technique and electrochemical cyclic voltammetry method. Our results provide a unique mechanism where high‐energy UV light promotes the Co3+/4+ conversion process in addition to the ordinary photoelectric effect excitation of the Co2+ material. Importantly, visible light under CSI can produce a photothermal effect for Co2+ excitation and Co3+/4+ conversion, which promotes the OER significantly more than the usual photoelectric effect. As a result, Co5.47N/CoN (containing 28% CoN) obtained 317.9% OER enhancement, which provides a pathway for constructing excellent OER catalysts.

A novel and efficient voltammetric sensor for the simultaneous determination of alizarin red S and tartrazine by using poly(leucine) functionalized carbon paste electrode

In the current work, a rapid, selective, and sensitive technique was developed for the detection of Alizarin Red S (ARS) by applying poly leucine modified carbon paste electrode (PLMCPE). Electrochemical impedance spectroscopy (EIS) and Scanning electron microscopy (SEM) were utilized to study the surface morphology of unmodified carbon paste electrode (UMCPE) and PLMCPE. The active surface area for UMCPE and PLMCPE was found to be 0.0012 cm2 and 0.0026 cm2 respectively. The electrochemical response of ARS at UMCPE and PLMCPE was analyzed using cyclic voltammetry (CV) in the potential window of 0.4 to 1.0 V. The cyclic voltammogram obtained for varying the pH of 0.2 M phosphate buffer (PB) solution showed maximum current for the oxidation of ARS at pH 6.5. The electrochemical reaction of ARS was found to be irreversible and adsorption controlled. The effect of variation of concentration of ARS on the oxidation peak current was evaluated using CV and linear scan voltammetry (LSV). A linear relationship between the concentration variation and current was obtained in the linear range of 1.5 μM–3.5 μM and 0.2 μM–5.0 μM for CV and LSV respectively. The limit of detection (LOD) of 0.68 μM for the CV method and 0.29 μM for the LSV method was exhibited by the developed sensor. The simultaneous study of ARS along with tartrazine (TZ) showed good selectivity for ARS. The interferents of foreign molecules showed no effect on the selectivity of the electrode. The applicability of PLMCPE on real samples gave good recovery ranging from 97.46–101.2%; hence, the sensor can be utilized on real samples. The developed sensor has good stability and sensitivity.

The setting and hardening of geopolymer concrete based on low-field nuclear magnetic resonance and cyclic voltammetry methods

The hydration process has an important influence on the various properties of geopolymer concrete. However, current testing methods for hydration degree are complex and inconvenient, which limits the wide application of geopolymer concrete. For this reason, this study innovatively proposes new methods for non-destructive characterisation of the hydration degree based on low-field nuclear magnetic resonance and cyclic voltammetry techniques. Meanwhile, the setting and hardening characteristics of red mud-coal metakaolin geopolymer concrete with water-binder (W/B) ratios of 0.50, 0.55, 0.60 and 0.65, respectively, was systematically and comprehensively evaluated. The reaction mechanism of geopolymer concrete was revealed using a variety of testing methods such as SEM-EDS, thermogravimetric, and heat of hydration. The results show that the degree of hydration is significantly correlated with the intensity-weighted relaxation time and specific capacitance value, which can be expressed by pertinent equations. In addition, it is found that the hydration process of geopolymer concrete is divided into different stages, forming two gel phases, C-A-S-H and N-A-S-H. Increasing the W/B ratio promotes the generation of C-A-S-H gels but severely hinders the generation of N-A-S-H gels, overall adversely affecting the hydration process. This work will facilitate non-destructive monitoring of the status of geopolymer concrete during actual projects to ensure construction safety.

Novel MoS2-decorated Cu2O hybrid nanoparticles for enhanced non-enzymatic electrochemical cholesterol detection

Precise identification of cholesterol levels is crucial for the early diagnosis of cardiovascular risk factors. This paper presents a novel approach for cholesterol detection that circumvents the reliance on enzymatic processes. Leveraging the unique properties of advanced materials and electrochemical principles, our non-enzymatic approach demonstrates enhanced sensitivity, specificity, and limit of detection in cholesterol analysis. A non-enzymatic electrochemical biosensor for Cholesterol, employing a nanohybrid comprising Cu2O nanoparticles decorated with MoS2, is presented. The cyclic voltammetry (CV), differential pulse voltammetry (DPV), and amperometry techniques were employed to investigate the electrochemical behaviour of the glassy carbon electrode modified with the Cu2O/MoS2 nanohybrid. The modified electrode exhibited an excellent sensitivity of 111.74 μA μM−1 cm−2 through the CV method and showcased a low detection limit of 2.18 μM and an expansive linear range spanning 0.1–180 μM when employing the DPV method. The electrode also showed good selectivity to various interfering components in 0.1 M NaOH and a satisfied stability of about 15 days at room temperature. The study demonstrates the potential for broader applications in clinical diagnostics and monitoring cardiovascular health, paving the way for a paradigm shift in cholesterol detection methodologies and offering a more efficient and cost-effective alternative to traditional enzymatic assays.

Rapid and Direct Detection of Trimethylamine N-oxide Using an Off-Chip Capacitance Biosensor with Readout SoC for Early-Stage Thrombosis and Cardiovascular Disease.

A demonstration of an off-chip capacitance array sensor with a limit of detection of 1 μM trimethylamine N-oxide (TMAO) to diagnose a chronic metabolism disease in urine is presented. The improved Cole-Cole model is employed to determine the parameters of R_catalyzed, C_catalyzed, and Rp_catalyzed, enabling the prediction of the catalytic resistance of enzyme, reduction effects of the analyte, and characterize the small signal alternating current properties of ionic strength caused by catalysis. Based on the standard solutions, we investigate the effects of pixel geometry parameters, driving electrode width, and sensing electrode width on the electrical field change of the off-chip capacitance sensor; the proposed off-chip sensor with readout system-on-chip exhibits a high sensitivity of 21 analog-to-digital converter counts/μM TMAO (or 2.5 mV/μM TMAO), response time of 1 s, repetition of 98.9%, and drift over time of 0.5 mV. The proposed off-chip sensor effectively discriminates TMAO in a phosphate-buffered saline solution based on minute changes in capacitance induced by the TorA enzyme, resulting in a discernible 2.15% distinction. These measurements have been successfully corroborated using the conventional cyclic voltammetry method, demonstrating a mere 0.024% variance. The off-chip sensor is crafted with a specific focus on detecting TMAO, achieved by excluding any reduction reactions between the TMAO-specific enzyme TorA and the compounds creatine and creatinine present in urine. This deliberate omission ensures that the sensor's attention remains solely on TMAO, thereby enhancing its precision in achieving accurate and reliable TMAO detection.

Investigation of the effect of carbonization temperature of plant biomass on the electrochemical properties of carbon material

Porous carbon materials (PСM) with different pore distributions in size and size of the specific surface area up to 250 m2/g were obtained by changing the carbonization temperature of plant biomass, namely walnut shells. The electrodes of electrochemical supercapacitors are formed based on the obtained carbon materials. The electrochemical behavior of PCM in 33% aqueous KOH solution has been studied by cyclic voltammetry and galvanostatic discharge-discharge methods and the value of their specific capacitance. The physicochemical processes occurring at the carbon electrode/electrolyte interface have been investigated by the method of impedance spectroscopy.

Cobalt and copper-based metal-organic frameworks synthesis and their supercapacitor application

In this study, two different metal-organic frameworks (MOFs) were synthesized using copper and cobalt metal ions with benzenedicarboxylic acid (bdc) as a common ligand. The prepared MOFs were characterized using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy-energy dispersive spectroscopy. Also, the electrochemical characteristics were analyzed using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy methods. Structural characterizations indicate that Co-bdc MOF is composed of three-dimensional non-uniform colloids and Cu-bdc MOF has a regular three-dimensional cuboidal structure, possessing good crystalline structure. The Cu-bdc MOF exhibited a maximum specific capacitance of 171 F/g, while Co-bdc MOF showed 368 F/g at the current density of 1 A/g. The solution resistance for the Co-bdc MOF was 0.09 Ω in comparison to 1.25 Ω for the Cu-bdc MOF. Also, the Co-bdc MOF demonstrated better cycling performance by retaining 85 % of its capacity after 2000 charge-discharge cycles. In contrast, the stability of the Cu-bdc MOF was lower, with only 78 % retention in capacity. Conclusively, the Co-bdc MOF demonstrated superior specific capacitance, lower resistance, and enhanced cyclic stability in 3 M KOH electrolyte system.

Chemical composition and biological properties of Thymus capitatus plants from Algerian high plains: A comparative and analytical study

Abstract The Lamiaceae family contains bioactive medicinal compounds mostly used as ornamental plants and traditional medicine, as well as in the food, cosmetics, and pharmaceutical sectors. Common uses include treating high cholesterol, diabetes, respiratory diseases, heart disease, and food poisoning. These medicinal uses were linked to their components and numerous biological properties, including antimicrobial and antioxidants. The goal of this study was to investigate the phytochemicals and biological activities of the petroleum ether extract of Thymus capitatus plant from two different regions of eastern Algeria (Souk ahras and Guelma), as well as to extract volatile oils using a Clevenger device and then analyze by using GC-MS. The results revealed that the total amount of phenolic compounds was better in the phenolic extract of Souk Ahras (3.41 mg GAE g−1), while the amount of flavonoid compounds was higher in the region of Guelma (26.31 mg QE g−1). Following the quantification of phenolic compounds by HPLC, we observed that the phenolic extracts contained most of the standard compounds in variable proportions. Furthermore, we tested the antioxidant activity of the phenolic compounds electrochemically with the cyclic voltammetry method. We concluded that the highest antioxidant content was recorded in the Guelma region extract (3.17 mg GAE g−1). We have also evaluated the antioxidant activity by a chemical method using 2,2-diphenyl-1-picrylhydrazyl, and the results showed that the Guelma extract exhibited a high effectiveness in terms of IC50% values. When extracting the volatile oils, it was found that the highest yield was in the Guelma region

Determination of the total antioxidant capacity of the Chinese tea based on a novel "peroxidase/zirconium phosphonate"composite electrochemical sensor.

In this work, a novel zirconium phosphonate (ZrPR1R2) was prepared by decorating both the aminoethoxy- group (R1) and the carboxypropyl- group (R2) on the zirconium phosphate layers in order to manipulate further the immobilization of the peroxidase (POD), and an antioxidant biosensor with higher sensitivity was constructed by dropping the POD/ZrPR1R2 composite onto the glassy carbon electrode surface. The activity of the POD/ZrPR1R2 composite was detected by Uv-vis spectra. The direct electrochemical behavior, the electrocatalytic response to dissolved oxygen and hydrogen peroxide, as well as the ability to detect total antioxidant capacity in tea sample were investigated by the methods of cyclic voltammetry. The results indicated that the immobilization of POD in ZrPR1R2 nanosheets matrix enhanced the enzymatic activity, and achieved the fast and direct electron transfer between POD and glassy carbon electrode. Moreover, the POD/ZrPR1R2 composite modified electrode show the electrocatalytic response to hydrogen peroxide in the linear range of 8.8×10-8 to 8.8×10-7 mol L-1, with the detection limit of 3.3×10-8 mol L-1. Attributing to the sensitive response to dissolved oxygen, the total antioxidant capacity can be detected directly in the real tea water by this POD/ZrPR1R2 composite modified electrode.

Synthesis and Characterization of Copper-Nickel Based Metal Organic Framework by Co-Precipitation Methode: Properties and Possible Application

CuNi-BTC was synthesized using the co-precipitation method with precursors copper (II) nitrate trihydrate, nickel nitrate trihydrate, benzene-1,3,5-tricarboxylic acid, and the addition of 10 wt% triethanolamine (TEOA) as a modulator. The synthesis was conducted at room temperature and dried at 60°C for 24 hours. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier-Transform Infrared (FTIR), Brunnauer-Emmet-Teller (BET), and electrochemical measurement are techniques employed for the characterization of the material. The diffraction patterns of CuNi-BTC show similar diffraction peaks of the HKUST-1 at 2θ of 6.7°, 9.5°, 11.5°, and 13.4°, respectively. The morphology of CuNi-BTC has an octahedral shape with a pore on its surface. The BET analyses show that the surface area of CuNi-BTC is 534 m2/g with pore and diameter volumes of 0.044 cm3/g and 1.60 nm, respectively. The nitrogen adsorption-desorption isotherm graph shows the type IV characteristic of a mesoporous material. The electrochemical performance of the material was observed by cyclic voltammetry (CV) methods. The CuNi-BTC has current reduction and oxidation values of 4.46 and 3.38 μA, respectively, and has good stability at various scan rates between 10 – 100 mvs-1.

Electrodeposition of CoFeS nanoflakes on Cu2O nanospheres as an ultrasensitive sensing platform for measurement of the hydrazine and hydrogen peroxide in seawater sample

Nanoarchitectured design of the metal sulfides with highly available surface and abundant electroactive centers and using them as electrocatalyst for fabricate the electrochemical sensors for the detection of hydrazine (N2H4) and hydrogen peroxide (H2O2) is challenging and desirable. Herein, Cu2O nanospheres powder is firstly prepared using chemical reduction of copper chloride and then drop-casted on the glassy carbon electrode (GCE) surface. In the next step, CoFeS nanoflakes are electrodeposited on Cu2O nanospheres by cyclic voltammetry method to form CoFeS/Cu2O nanocomposite as a detection platform for measuring N2H4 and H2O2. Accordingly, Cu2O nanospheres are not only used as substrate, but also guided the CoFeS nanoflakes to adhere to the electrode surface without need to any binder or conductive additive, which enhances the electrical conductivity of the sensing active materials. As the hydrazine sensor, the CoFeS/Cu2O/GCE displayed wide linear ranges (0.0001–0.021 mM and 0.021–1.771 mM), low detection limit (0.12 μM), very high sensitivities (103.33 and 21.23 mA mM−1 cm−2), and excellent selectivity. The as-made nanocomposite also exhibited low detection limit of 1.26 μM for H2O2 sensing with very high sensitivities (12.31 and 3.96 mA mM−1 cm−2) for linear ranges of 0.001–0.03 mM and 0.03–2.03 mM, respectively, and negligible response against interfering substances. The superior analytical performance of the CoFeS/Cu2O for N2H4 electro-oxidation and H2O2 electro-reduction can be attributed to structure stability, high electroactive surface area, and good availability to analyte species and electrolyte diffusion. Moreover, to examine the potency of the prepared nanocomposite in real applications, the seawater sample was analyzed and results display that the CoFeS/Cu2O/GCE can be utilized as a reliable and applicable platform for measuring N2H4 and H2O2.

Cyclic Voltammetry Method for Analysis of Phosphate Concentration in Water

Phosphate is a nontoxic element but a limiting element for productivity. Several methods have been established to analyze the phosphate concentration in water. This study aims to analyze phosphate concentration in water using the voltammetry method using cyclic voltammetry. Cyclic voltammetry is an electroanalytical method that measures the current outcome of oxidation-reduction reactions in response to the potential. The current outcome is directly proportional to the phosphate concentration in the solution. The calibration curve was formed from the KH2PO4 standard solution using concentrations of 0.1 mg/L, 0.2 mg/L, 0.4 mg/L, 0.8 mg/L, and 1.6 mg/L. The voltammogram showed that the analyte does not have an anode peak current (Ipa), which means that the analyte solution did not have an oxidation reaction, so the cathode peak current (Ipc) value was used. Based on the calibration curve, the linear regression graph with a straight-line equation is y = -0,00000645632x - 0,000208737 with R2 of 0,99737. Meanwhile, this cyclic voltammetry method was validated by calculating the LOD and LOQ values; the results are 0.1034 mg/L and 0.3134 mg/L, respectively. Hence, based on the analysis of phosphate concentration in water samples, this method works satisfactorily and is suitable for routine analysis because of its advantages.

Electrochemical studies: Biological evaluation of the homometallic‐binuclear complexes of malonate‐derived tetradentate O2N2 ligand

Novel metal complexes were synthesized by mixing N1,N3‐bis(4‐phenylthiazol‐2‐yl)malonamide with Cr (III), Fe (III), Cu (II), and Zn (II) nitrates in a 1:2 (L: metal) ratio. Through the use of several analytical and spectral methods, the structures of all compounds were determined. It was determined that the novel ligand functions through O2N2 sites as a neutral tetradentate. The thermal stability and the thermodynamic parameters were evaluated using thermal gravimetric analysis and the Coats‐Redfern equations. Powder X‐ray diffraction investigation revealed the type of unit cell and the degree of crystallinity. The complexes were further tested for their antibacterial efficacy, with molecular simulation using several proteins demonstrating the strongest action against a range of pathogens. Optimization for all compounds were made through the basis set DFT/B3LYP/LANL2DZ to find the theoretical stability, FMO orbitals, energy gaps, molecular electrostatic potentials (MEPs), and evaluate physical parameter. Here, the electrochemical properties of the metal complexes were investigated using cyclic voltammetry and electrochemical impedance spectroscopy methods. Additionally, [Cr2(L)(NO3)4(H2O)4](NO3)2 complex has been authorized that has high electrocatalytic characteristics, making it attractive for use in supercapacitor applications.

A Cluster-Type Self-Healing Catalyst for Stable Saline–Alkali Water Splitting

In electrocatalytic processes, traditional powder/film electrodes inevitably suffer from damage or deactivation, reducing their catalytic performance and stability. In contrast, self-healing electrocatalysts, through special structural design or composition methods, can automatically repair at the damaged sites, restoring their electrocatalytic activity. Here, guided by Pourbaix diagrams, foam metal was activated by a simple cyclic voltammetry method to synthesize metal clusters dispersion solution (MC/KOH). The metal clusters-modified hydroxylated Ni-Fe oxyhydroxide electrode (MC/NixFeyOOH) by a facile Ni-Fe metal–organic framework-reconstructed strategy, exhibiting superior performance toward the oxygen evolution reaction (OER) in the mixture of MC/KOH and saline–alkali water (MC/KOH+SAW). Specifically, using a nickel clusters-modified hydroxylated Ni-Fe oxyhydroxide electrode (NC/NixFeyOOH) for OER, the NC/NixFeyOOH catalyst has an ultra-low overpotential of 149 mV@10 mA cm−2, and durable stability of 100 h at 500 mA cm−2. By coupling this OER catalyst with an efficient hydrogen evolution reaction catalyst, high activity and durability in overall SAW splitting is exhibited. What is more, benefiting from the excellent fluidity, flexibility, and enhanced catalytic activity effect of the liquid NC, we demonstrate a self-healing electrocatalysis system for OER operated in the flowing NC/(KOH+SAW). This strategy provides innovative solutions for the fields of sustainable energy and environmental protection.

Facile electrochemical determination of sertraline at nanomolar concentration using bimetallic MXene NbTiCTx and MWCNTs hybridized electrodes as sensing platform

A novel and facile electrochemical determination of Sertraline at nanomolar concentration using bimetallic MXene NbTiCTx and MWCNTs hybridized electrodes as sensing platforms is demonstrated. NbTiCTx/MWCNTs composites were produced by etching NbTiAlC to obtain NbTiCTx, and ultrasonically mixing this with MWCNTs. An electrochemical sensor based on NbTiCTx/MWCNTs nanocomposite modified (NbTiCTx/MWCNTs/GCE) was constructed, for use in the sensitive detection of Sertraline (SER). The successful preparation of NbTiCTx/MWCNTs and the electrochemical performance of the electrodes were verified by Scanning electron microscopy, X-ray diffraction, cyclic voltammetry and electrochemical impedance characterization methods. The experimental results show that NbTiCTx/MWCNTs/GCE can increase the SER oxidation peak current, with two good linear relationships (R2 = 0.9910 and 0.9967) between the current and the concentration of SER (5.0–10.0 μM and 10.0–100.0 μM), with a detection limit of 0.16 μM (S/N = 3). The sensor has good selectivity, repeatability, reproducibility and stability, and enables the sensitive determination of SER in human serum and urine samples of clinical biological fluids. It is believed that this work is significant and is of broad interest for work in innovative material development and biomedical applications.