Differential Pulse Voltammetric Simultaneous Determination of Paracetamol and Omnipaque on Boron Doped Diamond Electrode: Application to Natural Tomato, Carrot, Cucumber Juices and Wastewater

This article describes the use of a boron-doped diamond electrode (BDDE) as an electrochemical sensor for the simultaneous determination of omnipaque (OMP) and paracetamol (PCM) in perchloric acid medium (HClO4 0.1 M) and in complex matrices such as tomato, carrot and cucumber juices and waste water from the Treichville University Hospital. Voltammetric studies allowed us to have well-defined oxidation peaks at distinct potentials of OMP (E = 0.5 V/SCE) and PCM (E = 0.7 V/SCE). Under optimized conditions, well-defined quantities of OMP and PCM, introduced simultaneously by metered additions, gave linear responses in concentration ranges of 259.8 - 467.2 μM for OMP and 58.73 - 116.3 μM PCM. The detection limits obtained are 7.23 μΜ and 3.6 μΜ respectively for OMP and PCM with recovery rates between 85.8% ± 0.1% and 92.6% ± 0.1% for OMP and between 99.9% ± 0.1% and 101.2% ± 0.4% for the PCM. This technique has been successfully used to simultaneously detect these pharmaceuticals in these complex environments. It allows recovery of OMP and PCM respectively up to 97.5% ± 0.0% and 91.6% ± 0.3% in tomato juice;100.0% ± 0.0% and 95.2% ± 0.2% in carrot juice;101.4% ± 0.1% and 97.3% ± 0.3% in cucumber juice;100.1% ± 0.9% and 100.9% ± 0.1% in wastewater. The relevance of this technique for the simultaneous detection of OMP and PCM in tomato, carrot, cucumber juices and in waste water can be studied in the context of the contamination of certain fruits and vegetables by the substances organic pharmaceuticals released into the environment without prior treatment.

Electronic Transport Properties of Diblock Co-Oligomer Molecule Devices Sandwiched between Nitrogen Doping Armchair Graphene Nanoribbon Electrodes

We investigate the electronic transport properties of dipyrimidinyl-diphenyl sandwiched between two armchair graphene nanoribbon electrodes using the nonequilibrium Green function formalism combined with a first-principles method based on density functional theory. Among the three models M1–M3, M1 is not doped with a heteroatom. In the left parts of M2 and M3, nitrogen atoms are doped at two edges of the nanoribbon. In the right parts, nitrogen atoms are doped at one center and at the edges of M2 and M3, respectively. Comparisons of M1, M2 and M3 show obvious rectifying characteristics, and the maximum rectification ratios are up to 42.9 in M2. The results show that the rectifying behavior is strongly dependent on the doping position of electrodes. A higher rectification ratio can be found in the dipyrimidinyl-diphenyl molecular device with asymmetric doping of left and right electrodes, which suggests that this system has a broader application in future logic and memory devices.

Preparation and Degradation Phenol Characterization of Ti/SnO_2-Sb-Mo Electrode Doped with Different Contents of Molybdenum

The Ti/SnO2-Sb-Mo electrodes doped with different molar ratios of molybdenum（Mo） were prepared by sol—gel method in order to investigate the effect of Mo on the characterization of Ti/SnO2-Sb—Mo electrodes.X-ray diffraction（XRD）,field-emission scanning electron microscopy（FE-SEM）,energy dispersive spectrometry（EDS）,and linear scanning voltammetry（LSV） were used to scrutinize the coating material and the electrochemical activity.The concentration of phenol,the value of total organic carbon（TOC）,the mineralization current efficiency（MCE） and the ultraviolet—visible spectroscopy（UV-Vis） spectrum of phenol solution were measured over the electrochemical degradation process of phenol to confirm the phenol degradation characterization of Ti/SnO2-Sb-Mo electrodes.Results showed that the electrode at the Mo content of 1 at.%provided optimal catalytic activity for phenol degradation and the longest life time.The removal percentage of phenol and TOC were 99.62%and82.67%,respectively.The Ti/SnO2-Sb-Mo electrode with 1 at.%of Mo reached maximum MCE of phenol oxidation.The kinetic investigation of phenol and TOC degradation displayed the pseudo-first order reaction model.The Ti/SnO2-Sb-Mo electrode coating with 7 at.%Mo presented the highest oxygen evolution overpotential,indicating the diverse effects for different Mo molar ratio doping.

Electro-catalytic degradation properties of Ti/SnO_2–Sb electrodes doped with different rare earths

Ti/SnO2–Sb electrode has a good effect on the removal of organic pollutants. But its short service life limits its large-scale application in industry. Electro-catalytic degradation performances and service life of the electrode can be significantly improved by doping rare earth（RE） ions into the oxide coating of Ti/SnO2–Sb electrode. Ti/SnO2–Sb electrodes doped with different RE elements（Ce, Dy, La, and Eu） were prepared by the thermal decomposition method at 550 ℃. Electro-catalytic degradation performances of electrodes doped with different RE elements were evaluated by linear sweep voltammetry（LSV） and Tafel curves. During the electrolysis,the conversion of p-nitrophenol was performed with these electrodes as anodes under galvanostatic control. The structures and morphologies of the surface coating of the electrodes were characterized by scanning electron microscope（SEM）. The results demonstrate that the electro-catalytic degradation performances of Ti/SnO2–Sb electrodes are improved to different levels by doping different RE ions. Improved Ti/SnO2–Sb electrodes by the introduction of different RE have higher oxygen evolution potential, better electro-catalysis ability, better coverage,and longer electrode life.

Structural, Optical and Electrical Properties of Ga Doped ZnO/Cu grid/Ga Doped ZnO Transparent Electrodes

Ga doped ZnO （OZO）/Cu grid/GZO transparent conductive electrode （TCE） structures were fabricated at room temperature （RT） by using electron beam evaporation （EBE） for the Cu grids and RF magnetron sputtering for the GZO layers. In this work, we investigated the electrical and optical characteristics of GZO/Cu grid/GZO multilayer electrode for thin film solar cells by using evaporated Cu grid and sputtered GZO thin films to enhance the optical transparency without significantly affecting their conductivity. The optical transmittance and sheet resistance of GZO/Cu grid/GZO multilayer are higher than those of GZO/Cu film/GZO multilayer independent of Cu grid separation distance and increase with increasing Cu grid separation distances. The calculation of both transmittance and sheet resistance of GZO/Cu grid] GZO multilayer was based on Cu filling factor correlated with the geometry of Cu grid. The calculated values for the transmittance and sheet resistance of the GZO/Cu grid/GZO multilayer were similar to the experimentally observed ones. The highest figure of merit ФTc is 5.18× 10^-3Ω^-1 for the GZO/Cu grid] GZO multilayer with Cu grid separation distance of 1 mm was obtained, in this case, the transmittance and resistivity were 82.72% and 2.17 × 10 ^-4Ωcm, respectively. The transmittance and resistivity are accentahle for nractical thin film snlar cell annlicatinn~

Highly nitrogen and sulfur dual-doped carbon microspheres for supercapacitors

Heteroatom doping, especially dual-doped carbon materials have attracted much attention for the past few years, and have been regarded as one of the most efficient strategies to enhance the capacitance behavior of porous carbon materials. In this work, a facile two-step synthetic route was developed to fab- ricate nitrogen and sulfur co-doped carbon microsphere （NSCM） by using thiourea as dopant. The NJS doping content is controlled via varying the carbonization temperature. It has been proved that a suitable quantity of N and S groups could not only provide pseudo-capacitance but also promote the electron transfer for carbon materials, which ensures the further utilization of the exposed surfaces for charge storage. The optimized NSCM prepared at a carbonization temperature of 800 ℃ （NSCM-800） achieves a capacitance of 277.1 F g^-1 at a current density of 0.3 A g^-1 in 6.0 mol L^-1 KOH electrolyte, which is 71% higher than that of undoped carbon microsphere. Besides, NSCM-800 shows an excellent cycling stability, 98.2% of the initial capacitance is retained after 5,000 cvcles at a current densitv of 3.0 A g^-1.