Electrochemical Behavior Of Catechol Research Articles

Photocatalytic, antibacterial and optoelectronic applications of Terbium doped Zinc oxide nanoparticles prepared via chemical co-precipitation method

This work demonstrates facile synthesis of Tb-doped ZnO nanoparticles and investigates their structural, optical, electrochemical, photocatalytic, and antibacterial performance. XRD patterns of undoped and doped ZnO nanoparticles confirm a hexagonal wurtzite structure. TEM and SAED reveals that the particle size is 14–38 nm. SEM images show that ZnO and Tb-doped ZnO nanoparticles have smooth surfaces, and elemental composition was confirmed by EDX analysis. UV–Visible spectrophotometry studies, reveals that the band gap narrows with increasing Tb concentration. Photoluminescence spectra at room temperature showed a band at 538 nm, indicating zinc vacancies and green emission. Tb-doped ZnO with x = 0.075 exhibited the highest photocatalytic activity for degrading Rose Bengal dye compared to other photocatalysts. The electrochemical behaviour of Catechol (CC), Hydroquinone (HQ), and Bisphenol-A (BPA) at Tb–ZnO/MCPE was studied. The modified electrode process for CC and BPA was adsorption-controlled, and simultaneous recognition of CC, HQ, and BPA was achieved, showing an increase in current. Electro polymerization of poly (Congo red) on Tb–ZnO/MCPE confirmed clean deposition on the surface, enhancing electrocatalytic activity. The antibacterial efficacy was tested using the traditional disc diffusion method, showing effective inactivation of bacterial strains, including pathogens such as S. aureus (G+) and E. coli (G-).

Waste hazelnut shell based effective hydrothermal carbon/SnO2 nanoparticles: Towards electrochemical sensing of catechol in green tea, fruit juice, and urine samples

This study focused on the electrochemical detection of catechol (CC), a carcinogenic for humans and a periodic environmental pollutant found in consumed food and beverages and has low degradability and high toxicity in the ecological environment. Also, in this study, for the first time, a new and green electrochemical detection platform was developed for the detection of CC through green carbon material (HZ) recycled from waste hazelnut shells with the hydrothermal carbonization technique (HTC) and SnO2 nanoparticles (NPs). The morphology, surface chemistry, chemical structure, and physicochemical properties of the synthesized green-based functional carbon material and SnO2 NPs were thoroughly investigated and elucidated using different characterization techniques. Thus, a green perspective was contributed to the studies of researchers working on CC detection in designing new types of nanosensors and developing electrode modifications. On GCE with an HZ-SnO2 modification, the effects of pH, the supporting electrolyte, and the scan rate on the electrochemical behavior of CC were investigated. The limit of detection (LOD) of the proposed nanosensor for CC was determined as 8.51 nM and the linearity range was determined as 0.80–80 µM under optimal conditions using adsorptive stripping differential pulse voltammetry (AdsDPV).The developed new type, the green method, has been performed to detect the CC in green tea, fruit juice, and urine samples with sufficient accuracy and precision.

Electrochemical studies of catechol at ordinary and mesoporous platinum electrodes via convolutive voltammetry and numerical simulation methods

On the normal platinum electrode and mesoporous Pt electrode, the electrochemical behaviour of catechol was studied using convolutive cyclic voltammetry and numerical simulation. The nanostructured mesoporous platinum structure was electrochemically deposited from the hexadic liquid crystalline template of C16EO8 surfactant. The electrocatalytic feature and reversibility of the mesoporous platinum electrode within the oxidation of catechol in 1.0 M HClO4 have been found to be extraordinary. At ordinary and mesoporous platinum electrodes, the separation between the peaks (∆Ep) became reduced from 430 to 75 mV vs. SCE. Catechol cyclic voltammograms show one anodic peak inside the forward scan, but the corresponding cathodic one disappears in the reverse direction, and a new peak is observed at a lower potential value at the ordinary Pt electrode. In the case of the mesoporous Pt electrode, the voltammogram gives one anodic peak inside the first scan of potential and one cathodic peak inside the reverse direction. On the basis of the electrochemical behaviour, we conclude an ECEC mechanism for the electrochemical oxidation of catechol in 1.0 M HClO4 at each electrode. A numerical simulation was used to verify the proposed electrode response.Graphical

Salicylaldehyde functionalized chitosan for electrochemical sensitive sensor: Simultaneous determination of catechol and hydroquinone

Salicylaldehyde functionalized chitosan (S-CHIT) was prepared and electrochemical sensor based on the above material and acetylene black paste electrode (ABPE) were constructed. A new method for the simultaneous detection of catechol (CC) and hydroquinone (HQ) was established. The results of Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) showed that S-CHIT had been successfully synthesized and attached to the surface of ABPE. Cyclic voltammetry (CV) and second-order derivative linear sweep voltammetry (SDLSV) were used to investigate the electrochemical behaviors of CC and HQ on the S-CHIT/ABPE. In 0.1 M H2SO4 solution, CC and HQ produced a pair of reversible redox peaks with good shape on the modified electrode. The quantitative determination of CC and HQ was performed by SDLSV using the oxidation signal. The difference of the oxidation peak potentials between CC and HQ was 112 mV. In the presence of 50 µM of the respective isomer, the linear concentration range of CC and HQ is 0.6 μM to 80 μM and 1.0 μM to 80 μM respectively, and the corresponding detection limits are 0.1 μM and 0.4 μM. The method was applied to the simultaneous determination of CC and HQ in water samples. The results show that S-CHIT/ABPE is a promising electrochemical sensor for the simultaneous detection of CC and HQ.

Fabrication of Efficient and Selective Modified Graphene Paste Sensor for the Determination of Catechol and Hydroquinone

An electrochemical sensor, based on a graphene paste electrode (GPE), was modified with a polymerization method, and the electrochemical behavior of catechol (CC) and hydroquinone (HQ) was investigated using electroanalytical methods like cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The effect of CC at the modified electrode was evidenced by the positive shift of the oxidation peak potential of CC at the poly (rosaniline)-modified graphene paste electrode (PRAMGPE) and the nine-fold enhancement of the peak current, as compared to a bare graphene paste electrode (BGPE). The sensitivity of CC investigated by DPV was more sensitive than CV for the analysis of CC. The DPV method showed the two linear ranges of 2.0 × 10−6–1.0 × 10−5 M and 1.5 × 10−5–5 × 10−5 M. The detection limit and limit of quantification were determined to be 8.2 × 10−7 and 27.6 × 10−7 M, respectively. The obtained results were compared successfully with respect to those obtained using the official method. Moreover, this sensor is applied for the selective determination of CC in the presence of HQ. The high sensitivity, good reproducibility, and wide linear range make the modified electrode suitable for the determination of CC in real samples. The practical application of the sensor was demonstrated by determining the concentration of CC in water samples with acceptable recoveries (97.5–98%).

Amino-grafting of montmorillonite improved by acid activation and application to the electroanalysis of catechol

In this work, a natural sodium-montmorillonite clay mineral (Mt-Na) was functionalized with aminegroups, either by direct grafting (Mt-NH2) or via acid activation followed by grafting (MtH-NH2) of [3(2-aminoethyl)amino)]propyltrimethoxysilane (AEP-TMS). The morphology and structure of the resulting composite materials were characterizedby scanning electron microscopy, X-ray diffraction, N2 adsorption-desorption isotherms (BET method) infrared spectroscopy, CHN elemental analysis and thermogravimetric analyses (TGA). The obtained organoclays were then used to modify the surface ofa glassy carbon electrode (GCE), and the permselectivity and accumulation properties of the resulting films were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results indicated that MtH-NH2 modified GCE (GCE/MtH-NH2) exhibited some charge selectivity features and can be applied to the electrochemical oxidation of catechol (CT).By plotting the double logarithmic variation of anodic peak currents (Ipa) versus potential scan rate, the obtained slope valueof 0.49 revealed a diffusion-controlled electron-transfer mechanisms for the redox process. The electrochemical behavior of CT on the modified electrode was also studied using differential pulse voltammetry (DPV). The sensitivities of GCE/MtH-NH2 for CT were 1.71, 3.87 and 1.35-fold greater than signals obtained on the bare GCE, GCE/Mt-Na and GCE/Mt-NH2 respectively, due to the ability of the aminated materials to strongly accumulate CT. After optimization, GCE/MtH-NH2 was used for CT determination by differential pulse voltammetry that gave rise to a linear response in the concentration range from 5 μM to 80 μM (R2 = 0.999), and to a detection limit of 0.65 μM. The proposed method was applied to CT detection in water samples and in a tea sample.

Electrochemical Polymerised Graphene Paste Electrode and Application to Catechol Sensing

Objective: To build up an advantageous strategy for sensitive determination of catechol (CC), a poly (proline) modified graphene paste electrode (PPMGPE) was fabricated and used as a voltammetric sensor for the determination of CC. Methods: The performance of the modified electrode was studied using cyclic voltammetric (CV) and differential pulse voltammetric method (DPV). The modified electrode was characterized by CV and DPV. The surface of the modified electrode was examined by FESEM. The electrochemical behavior of CC in phosphate buffer solution (pH 7.5) was inspected using bare graphene paste electrode (BGPE) and PPMGPE. Results & Conclusion: The PPMGPE shows a lower limit of detection, calculated to be 8.7×10–7mol L−1 (S/N=3). This modified electrode was applied successfully for the determination of CC in water samples without applying any sample pretreatment.

Analytical application of the poly(1H-1,2,4-triazole-3-thiol) modified gold electrode for high-sensitive voltammetric determination of catechol in tap and lake water samples

ABSTRACTIn this work, a simple, sensitive and rapid method for the determination of trace amounts of catechol (CT) in aqueous media has been suggested. For this purpose, poly(1H-1,2,4-triazole-3-thiol) film was electrochemically deposited successfully at the gold electrode (Au/T3T). The electrochemical behaviour of CT was studied on the Au/T3T electrode by the cyclic voltammetry and differential pulse voltammetry techniques. The anodic peak current value and the concentration of CT showed a good linear relationship in the range of 0.015–2.8 µM. The limit of detection was found as 1.88 nM (S/N = 3). Besides, the reproducibility, repeatability, stability and interference measurements were also assayed. This sensor was applied successfully for the detection of CT in synthetic and real samples.

The Investigation of Electrochemical Behavior of Catechol at Conducting Polymer Electrodes

The Investigation of Electrochemical Behavior of Catechol at Conducting Polymer Electrodes

Highly Sensitive Temperature‐responsive Sensor Based on PS‐PDEA‐PS/C60‐MWCNTs for Reversible Switch Detection of Catechol

AbstractA new type of temperature‐responsive electrochemical sensor was constructed based on a glass carbon electrode modified by the composite containing temperature‐responsive polymer polystyrene‐poly N, N‐diethyl acrylamide‐polystyrene (PS‐PDEA‐PS) and fullerenes‐carboxylate multi‐walled carbon nanotubes (C60‐MWCNTs). The sensor was used for the electrochemical detection of catechol (CC). When the temperature is higher than the critical temperature (LCST) of PS‐PDEA‐PS, the electrochemical behavior of CC can be detected, which it is in the “on” state. When the temperature is lower than LCST, the composite modified film is in the “off” state and the electrochemical behavior of CC was not detected. Under the best experimental conditions, the sensor has a good detection range for catechol from 4.0 to 135.0 μM, with a LOD of 1.45 μM. In addition, the proposed sensor has good stability and reproducibility, and was successfully applied to the determination of catechol in real tap water.

An electronic device based on gold nanoparticles and tetraruthenated porphyrin as an electrochemical sensor for catechol.

The aim of this study was to obtain an electrochemical device between the electrostatic interaction of the electropolymerized porphyrin {CoTPyP[RuCl3(dppb)]4}, where TPyP = 5,10,15, 20-tetrapyridilphorphyrin and dppb = 1,4-bis(diphenylphosphino)butane, and gold nanoparticles (AuNPsn−), to be used as a voltammetric sensor to determine catechol (CC). The modified electrode, labelled as [(CoTPRu4)n8+-BE]/AuNPsn− {where BE = bare electrode = glassy carbon electrode (GCE) or indium tin oxide (ITO)}, was made layer-by-layer. Initially, a cationic polymeric film was generated by electropolymerization of the {CoTPyP[RuCl3(dppb)]4} onto the surface of the bare electrode to produce an intermediary electrode [(CoTPRu4)n8+-BE]. Making the final electronic device also involves coating the electrode [(CoTPRu4)n8+-BE] using a colloidal suspension of AuNPsn− by electrostatic interaction between the species. Therefore, a bilayer labelled as [(CoTPRu4)n8+-BE]/AuNPsn− was produced and used as an electrochemical sensor for CC determination. The electrochemical behaviour of CC was investigated using cyclic voltammetry at [(CoTPRu4)n8+-GCE]/AuNPsn− electrode. Compared to the GCE, the [(CoTPRu4)n8+-GCE]/AuNPsn− showed higher electrocatalytic activity towards the oxidation of CC. Under the optimized conditions, the calibration curves for CC were 21–1357 µmol l−1 with a high sensitivity of 108 µA µmol l−1 cm−2. The detection limit was 1.4 µmol l−1.

Electrochemical Determination of Catechol Based on Cadmium Telluride Quantum Dots/Graphene Composite Film Modified Electrode

A novel electrochemical sensor of catechol based on cadmium telluride quantum dots (CdTe QDs) /graphene (GR) composite film modified electrode was prepared by using the method of electrodeposition of the GR and dispensing CdTe QDs on the glassy carbon electrode (GCE). Meanwhile, the electrochemical behavior of catechol (CC) was studied by using cyclic voltammetry (CV) and differential pulse method (DPV). The experimental results showed the oxidation peak current of the CC on the modified electrodes had a significant enhancement compared with bare GCE. The oxidation peak current exhibited a good linear relationship in the concentration range from 30 to 1000 μmol L−1 (R = 0.9904) and the detection limit (LOD) was 18.28 μmol L−1 (S/N = 3),the quantification limit (LOQ) was 60.94 μmol L−1 (S/N = 10). And the repeatability of the method was also studied, the relative standard deviation (RSD) of the oxidation peak current was 3.79%. The prepared electrode showed good reproducibility, stability and was successfully applied to the actual sample testing, the result was satisfactory.

Electrochemical Behaviour of Dihydroxybenzene Isomers at Glassy Carbon Electrode in Different Electrolytic Media

Electrochemical behaviour of catechol, hydroquinone and resorcinol was investigated in KCl, acetate buffer and phosphate buffer at glassy carbon electrod using cyclic voltammetry. The results imply that the glassy carbon electrode exhibited a synergistic and excellent electrocatalytic effect on the redox behaviors of the benzenediols. Catechol and hydroquinone show one pair of redox peaks in acetate and phosphate buffer but two pairs of redox peaks in KCl. In all cases the redox process is quasireversible. Resorcinol behaves almost irreversibly in all three electrolytic media. Good linear relationships were obtained between the peak currents and the concentrations of benzenediols. The electrochemical process in all the isomers was controlled by diffusion process.Journal of Bangladesh Academy of Sciences, Vol. 39, No. 2, 135-146, 2015

Electrochemical sensing of catechol using a glassy carbon electrode modified with a composite made from silver nanoparticles, polydopamine, and graphene

We report on the modification of a glassy carbon electrode with a composite consisting of silver nanoparticles (AgNPs), polydopamine, and graphene to give an electrochemical sensor for catechol. The composite was characterized by transmission electron microscopy, and the electrochemical behavior of catechol at the modified electrode was studied by cyclic voltammetry. The electrochemical response is greatly enhanced and thought to result from a combination of beneficial effects including the good conductivity and large surface area of the AgNPs, the high conductivity of graphene, the synergistic effects of the composite, and the increased quantity of catechol that is adsorbed on the surface of the electrode. Differential pulse voltammetric responses are proportional to the concentration of catechol between 0.5 and 240 μM levels of catechol, and the detection limit is 0.1 μM (S/N = 3). The performance of the sensor was evaluated with catechol-spiked water samples, and recoveries range from 96.5 % to 103.1 %. The results indicated that the composite presented here is a promising substrate for use in electrochemical sensing.

Electrochemical Properties and Simultaneous Determination of Catechol, Resorcinol and Hydroquinone on Gold Electrode

Electrochemical behaviors of catechol(CAT),resorcinol(RE) and hydroquinone(HQ) in 0.5 mol/L sulfuric acid aqueous solution were studied using cyclic voltammetry.Voltammetric behaviors of CAT,Re and HQ in the coexisting system were studied using cyclic voltammetry and differential pulse voltammetry method.The results show that obvious separation effect is achieved under conditions of pH=0(sulfuric acid),scan rate of 10 mV/s,and scan potential of 0~1.2 V(vs.Ag/Cl).Under optimal conditions,the detection limit was 3.9×10-6,3.9×10-6 and 7.8×10-6 mol/L for CAT,RE,and HQ,respectively,in mixture of three substances using differential pulse voltammetry.The method is applied in the analysis of synthesized samples,and the accuracy and precision well satisfy the requirements of the analysis.

Sensitive Electrochemical Determination of Catechol with a Graphene Modified Carbon Ionic Liquid Electrode

AbstractIn this paper a graphene (GR) modified carbon ionic liquid electrode (CILE) was fabricated and used as the voltammetric sensor for the sensitive detection of catechol. Due to the specific physicochemical characteristics of GR such as high surface area, excellent conductivity and good electrochemical properties, the modified electrode exhibits rapid response and strong catalytic activity with high stability toward the electrochemical oxidation of catechol. A pair of well‐defined redox peaks appeared with the anodic and the cathodic peak potential located at 225 mV and 133 mV (vs.SCE) in pH 6.5 phosphate buffer solution, respectively. Electrochemical behaviors of catechol on the GR modified CILE were carefully investigated and the electrochemical parameters were calculated with the results of the electrode reaction standard rate constant (ks) as 1.24 s−1, the charge transfer coefficient (α) as 0.4 and the electron transfer number (n) as 2. Under the selected conditions the differential pulse voltammetric peak current increased linearly with the catechol concentrations in the range from 1.0 × 10‐7 to 7.0 × 10−4mol L‐1 with the detection limit as 3.0 × 10−8mol L‐1 (3σ). The proposed method was further applied to the synthetic waste water samples determination with satisfactory results

Electrochemical Detection of Catechol on Boron‐doped Diamond Electrode Modified with Au/TiO2 Nanorod Composite

AbstractAu/TiO2 nanorod composites with different ratios of [TiO2]:[Au] have been prepared by chemically reducing AuCl4‐ on the positively charged TiO2 nanorods surface and used to modify boron‐doped diamond (BDD) electrodes. The electrochemical behaviors of catechol on the bare and different Au/TiO2 nanorod composites‐modified BDD electrodes are studied. The cyclic voltammetric results indicate that these different Au/TiO2 nanorod composites‐modified BDD electrodes can enhance the electrocatalytic activity toward catechol detection, as compared with the bare BDD electrode. Among these different conditions, the Au/TiO2‐BDD3 electrode (the ratio of [TiO2]:[Au] is 27:1) is the most choice for catechol detection. The electrochemical response dependences of the Au/TiO2‐BDD3 electrode on pH of solution and the applied potential are studied. The detection limit of catechol is found to be about 1.4 × 10‐6 M in a linear range from 5 × 10‐6 M to 200 × 10‐6 M on the Au/TiO2‐BDD3 electrode.

Electrochemical behavior of catechol, resorcinol and hydroquinone at graphene–chitosan composite film modified glassy carbon electrode and their simultaneous determination in water samples

Graphene–chitosan composite film modified glassy carbon electrode was prepared and characterized. The fabricated electrode showed excellent electrochemical catalytic activities towards the oxidation of catechol (CT), resorcinol (RS) and hydroquinone (HQ). The oxidation overpotentials of CT, RS and HQ decreased significantly and the corresponding oxidation currents increased remarkably compared with those obtained at the bare GCE and chitosan modified GCE. Some kinetic parameters, such as the electron transfer number ( n), proton transfer number ( m), charge transfer coefficient ( α) and the apparent heterogeneous electron transfer rate constant ( k s), were calculated. Differential pulse voltammetry was used for the simultaneous determination of CT, RS and HQ in their ternary mixture. The peak-to-peak potential separations between CT and RS, RS and HQ, and HQ and CT were 0.388, 0.484 and 0.096 V, respectively. The calibration curves for CT, RS and HQ were obtained in the range of 1 × 10 −6 to 4 × 10 −4, 1 × 10 −6 to 5.5 × 10 −4 and 1 × 10 −6 to 3 × 10 −4 mol L −1, respectively. The detection limits were 7.5 × 10 −7 mol L −1 ( S/ N = 3).

Investigation of the electrochemical behavior of catechol and 4-methylcatechol in the presence of methyl mercapto thiadiazol as a nucleophile: application to electrochemical synthesis

The present study concerns the electrochemical behavior of catechol and 4-methylcatechol in the presence of 2-mercapto-5-methyl-1,3,4-thiadiazole (MMT) in aqueous medium on the surface of the glassy carbon electrode by means of cyclic voltammetry and controlled-potential coulometry. The oxidation mechanism was deduced from voltammetric and spectrophotometric data. The electro-generation of quinoid intermediates and their subsequent Michael-type reaction with MMT has been investigated as a clean and convenient strategy for the synthesis of corresponding reaction products. In addition, electro-synthesis of Michael addition products has been successfully accomplished by controlled-potential coulometry in a divided H-type cell in mild conditions that can be considered as a green procedure. The reaction products were characterized by spectrophotometric, 1H and 13C NMR, and mass spectrometric methods.

Electrochemical behavior of catechol in the presence of 2-methyl-1,3-cyclopentanedione: application to electrosynthesis

Electro-oxidation of catechol in the presence of 2-methyl-1,3-cyclopentanedione as a nucleophile was investigated in water–acetonitrile (90:10 v/v) solution. The results indicate that the o-benzoquinone electrogenerated participates in a Michael addition reaction with this nucleophile. The electrosynthesis of 2-(3,4-dihydroxyphenyl)-2-methylcyclopentane-1,3-dione was carried out. The product was characterized by NMR, MS, FT-IR, and elemental analysis. An EC mechanism was deduced from voltammetric and spectroscopic data. Also, the Michael addition reaction rate constant (k m) was estimated using digital simulation of voltammograms.