Electrocatalytic Oxidation of Calcium Folinate on Carboxyl Graphene Modified CuxO/Cu Electrode

Carboxyl graphene modified CuxO/Cu electrode was fabricated. The bare copper electrode was firstly anodic polarized in 1.0 mol/L NaOH solution in order to get CuxO nanoparticles, then the carboxyl graphene （CG） was electrodeposited on the CuxO/Cu electrode by cyclic potential sweeping. The electrocatalytic oxidation behaviors of calcium folinate （CF） at the graphene modified CuxO/Cu electrode were investigated by cyclic voltammetry. A positive scan polarization reverse catalytic voltammetry was used to obtain the pure catalytic oxidation current. The graphene modified CuxO/Cu electrode was served as the electrochemical sensor of CF, a highly sensitivity of 22.0μA.（μmol/μL）^-1cm^-2 was achieved, and the current response was linear with increasing CF concentration in the range of 2.0×10^-7 mol/L to 2.0×10^-5 mol/L, which crossed three orders of magnitude, and the detection limit was found 7.6×10^-5 mol/L （S/N=3）. In addition, the proposed sensor was successfully applied in determination of CF in drug sample.

Facet effect on the reconstructed Cu-catalyzed electrochemical hydrogenation of 5-hydroxymethylfurfural(HMF) towards 2,5-bis(hydroxymethy)furan (BHMF)

The electrochemical hydrogenation of HMF to BHMF is an elegant alternative to the conventio nal thermocatalytic route for the production of high-value-added chemicals from biomass resources.In virtue of the wide potential window with promising Faradic efficiency(FE) towards BHMF,Cu-based electrode has been in the center of investigation.However,its structure-activity relationship remains ambiguous and its intrinsic catalytic activity is still unsatisfactory.In this work,we develop a two-step oxidation-reduction strategy to reconstruct the surface atom arrangement of the Cu foam(CF).By combination of multiple quasi-situ/in-situ techniques and density functional theory(DFT) calculation,the critical factor that governs the reaction is demonstrated to be facet effect of the metallic Cu crystal:Cu(110) facet accounts for the most favorable surface with enhanced chemisorption with reactants and selective production of BHMF,while Cu(100) facet might trigger the accumulation of the by-product 5,5'-bis(hydroxy methy)hydrofurion(BHH).With the optimized composition of the facets on the reconstructed Cu(OH)_(2)-ER/CF,the performance could be noticeably enhanced with a BHMF FE of 92.3% and HMF conversion of 98.5% at a potential of -0.15 V versus reversible hydrogen electrode(vs.RHE) in 0.1 M KOH solution.This work sheds light on the incomplete mechanistic puzzle for Cu-catalyzed electrochemical hydrogenation of HMF to BHMF,and provides a theoretical foundation for further precise design of highly efficient catalytic electrodes.

Metal chalcogenide complex-mediated fabrication of Cu_2S film as counter electrode in quantum dot sensitized solar cells

Cu2S film onto FTO glass substrate was obtained to function as counter electrode for polysulfide redox reactions in CdS/CdSe co-sensitized solar cells by sintering after spraying a metal chalcogenide complex, N4H9Cu7S4 solution. Relative to Pt counter electrode, the Cu2S counter electrode provides greater electrocatalytic activity and lower charge transfer resistance. The pre- pared CuzS counter electrode represented nanoflower-like porous film which was composed of Cu2S nanosheets on FTO and had a higher surface area and lower sheet resistance than that of sulfided brass Cu2S counter electrode. An energy conversion efficiency of 3.62% was achieved using the metal chalcogenide complex-mediated fabricated Cu2S counter electrode for CdS/CdSe co-sensitized solar cells under 1 sun, AM 1.5 illumination.

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~

Cathodic behavior of scandium(Ⅲ) on reactive copper electrodes in LiF-CaF_(2)eutectic molten salt

The electrochemical formation of Sc-Cu alloy was investigated in LiF-CaF_(2) eutectic molten salt employing various electrochemical methods.Cyclic voltammetry and square wave voltammetry indicate that the reduction of scandium(Ⅲ) on the tungsten electrode is a one-step reduction process with three electrons transfer.And underpotential deposition of scandium on the copper electrode occurs owing to the depolarization effect,i.e.,forming Sc-Cu intermetallic compounds.The thermodynamic properties of the Sc-Cu intermetallic compounds ScCu_(4),ScCu_(2),and ScCu in the temperature range of 1153-1223 K were estimated by open-circuit chronopotentiometry.Moreover,the Sc-Cu alloys were prepared by potentiostatic electrolysis and characterized by optical microscope,X-ray diffraction,scanning electron microscopy,and energy dispersive spectroscopy.The results reveal that only Sc-Cu alloy composed of Cu-ScCu_(4) can be synthesized at low cathodic current density and above eutectic temperature.