Search results for "Amperometry"
showing 10 items of 28 documents
(Photo)catalyst Characterization Techniques
2019
Abstract This chapter reports on some characterization techniques that are commonly used for catalysts and photocatalysts. Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), UV–visible (UV–Vis), photoluminescence (PL), and electrochemical characterization techniques are presented with experimental details and actual case studies from literature are discussed. The chapter starts with adsorption phenomena on (photo)catalysis and adsorption isotherms are presented. Then BET analysis technique and its applications in (photo)catalysis are explained. Morphological properties (SEM), functional groups, and the interaction of substrate (…
A nanostructured sensor of hydrogen peroxide
2017
Abstract A nanostructured electrochemical sensor of hydrogen peroxide was fabricated growing self-standing Pd nanowires (Pd NWs) into polycarbonate (PC) membranes through a simple metal galvanic deposition. Conditions of deposition were adjusted in order to attain 2–5 μm long Pd wires. Characterization of Pd-NWs was performed by scanning electrode microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. Properties of the nanostructured sensor were studied by cyclic voltammetry and chronoamperometry in phosphate buffer—ethanol solution. Addition of pure ethanol to the test solution was essential in order to increase wettability of the nanostructures. Sensing features were comp…
Bending Sensors Based on Thin Films of Semitransparent Bithiophene-Fulleropyrrolidine Bisadducts
2020
In this study, a novel bithiophene‐fulleropyrrolidine bisadducts system (bis‐Th2PC 60 ) was synthesized and electropolymerized by chronoamperometry onto flexible ITO/PET substrates. The resulting semitransparent thin film was characterized by XPS, FT‐IR, cyclic voltammetry and optical techniques, confirming the good outcome of the electropolymerization process. AFM investigations permitted to highlight an inherent disordered granular morphology, in which the grain‐to‐grain separation depends upon the application of bending. The electrical resistance of the thin film was characterized as function of bending (in the range 0°‐90°), showing promising responsivity to low bending angles (10°‐30°)…
Fabrication of a biocompatible and continuous glucose biosensor with the poly(3,4-ethylenedioxythiophene) modified electrode
2019
Abstract In this study, we have explored the potentiality of using GOx/AuNP/PEDOT(BSA)/Pt electrode as an implantable, long-lasting, and sensitive glucose biosensor. We have examined the performance of the electrode for glucose calibration with three electrochemical measurements, such as cyclic voltammetry, linear sweep voltammetry, as well as chronoamperometry, which all exhibited strong linear correlation between resulting signal and glucose concentration. In comparison, linear sweep voltammetry gave the best linear sensitivity, whose average was about 3.124 µA/mM/cm2 within a wide glucose concentration range from 0.416 to 50 mM. Meanwhile, the stability of the electrode was confirmed by …
Graphene electrochemical responses sense surroundings
2012
Abstract Graphite oxide (GO) paper, obtained by direct filtration of exfoliated GO in water over PTFE membrane filters, was reduced by using hydrazine vapours. The graphene-paper thus obtained was characterized by the combination of different techniques. The electrochemical characterization by cyclic voltammetry, chronoamperometry and chronopotentiometry presents a strong influence of the working conditions: temperature, electrolyte concentration and current on the electrochemical responses, indicating a good ability of the material to sense ambient and working conditions. Electrochemical devices based on graphene are expected to work as dual, and simultaneous, sensing-actuators.
Scanning electrochemical microscopy and electrochemical impedance spectroscopy-based characterization of perforated polycarbonate membrane modified b…
2021
Abstract In this research, scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were applied for the evaluation of surface characteristics of electrochemical (amperometric) biosensor based on two composite structures consisting of perforated polycarbonate membrane modified by carbon-nanomaterials and glucose oxidase. The first structure consisted of the polycarbonate filter membrane, punctured by 400 nm holes (PCM) consequently modified with single walled carbon nanotubes (SWCNT) and graphene oxide (GO) layer (PCM/SWCNT/GO); and the other structure consisted of the same PCM, consequently modified with SWCNT and reduced graphene oxide (rGO) layer (PCM/S…
The Determination of Carbohydrates by High-Performance Anion-Exchange Chromatography Coupled with Pulsed Amperometric Detection (HPAEC-PAD)
2021
Chromatography techniques are widely used to separate, identify, and quantify molecules depending on their physicochemical properties. Standard methods range from simple size exclusion to separation based on affinity or ion exchange. Here, we present a method for the direct analysis of carbohydrates in Magnaporthe oryzae using high-performance anion-exchange chromatography (HPAEC) coupled with pulsed amperometric detection (PAD). The combination of HPAEC with PAD provides the highest selectivity and sensitivity with minimal sample preparation and cleanup time. Utilizing our HPAEC-PAD approach, we obtain reliable and highly reproducible determination of carbohydrates produced as osmotic stre…
Photoelectrocatalysis of paracetamol on Pd–ZnO/ N-doped carbon nanofibers electrode
2021
Abstract The presence of pharmaceuticals in water bodies has become a major concern in recent years. An efficient and innovative way of eliminating these pollutants is through photoelectrocatalytic (PEC) degradation owing to its environmental sustainability and its ability to remove recalcitrant pollutants. In this study, palladium loaded zinc oxide/carbon nanofibers (CZnO–Pd) were employed as a novel photoanode for PEC degradation of paracetamol. The CZnO–Pd composite was prepared through electrospinning and atomic layer deposition (ALD). The obtained materials were characterized. Photoelectrochemical studies were carried out with linear sweep voltammetry and chronoamperometry. The removal…
Low angle bending detection semi-transparent piezoresistive sensor
2022
We designed, fabricated, and validated a piezoresistive bending sensor, a fundamental component of wearable electronic devices for monitoring human motion. The most diffused opaque carbon-based resistance flex sensors suffer from low detection for small bending angles. The sensor we here present is based on a semi-transparent active material (fulleropyrrolidine bisadducts polymer) and has the remarkable advantage of good electrical properties for low bending angles. The fabrication steps are effective since a pre-patterned ITO/PET surface is functionalized by chronoamperometric deposition, and the silver electrical contacts are inkjet printed. We propose a fitting function of the measured t…
Quantification of electrochromic kinetics by analysis of RGB digital video images
2018
A new, rapid, and practical procedure to obtain quantitative kinetic information of electrochromic materials is proposed. When the transition between two colors on a colored electrode surface is monitorized by digital video, the analysis of pixel color intensity (I) in sequential RGB digital images allows us to precise the half-life time (t1/2) of the color change since a maximum value of the standard deviation of the pixel intensity (σ(I)) is reached. We simulated and analyzed the evolution of standard deviation during an electrochromic transition in different circumstances (kinetic and diffusion control). As an example of application, electrochromic transitions of a thin film model, the P…