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Abstract: Sulfosalicylic acid (C7H6O6S) as a special additive was applied to favor the deposition of pure zinc sulfide (ZnS) nanocrystal thin films on ITO substrates from acidic solutions by potentiostatic technique with subsequent annealing. XRD, EDX, Raman, SEM and UV–vis–NIR analyses demonstrate that a proper concentration of C7H6O6S additive (0.2mM) in the electrolyte containing 20mM Zn2+, 20mM S2O3 2−, 0.375mM SO3 2− and 200mM LiCl can greatly contribute to the controllable growth of pure cubic ZnS film along (200) orientation at potential of −1.1V vs. SCE. The film possesses a uniform surface with an average crystallite size ca. 40.9nm, and a band gap ca. 3.68eV. Electrochemical studies indicate that C7H6O6S could adsorb on ITO surface and act as a hydrogen bond donor for free Cl−. The adsorption of C7H6O6S blocks some active sites used for the deposition of S, while the role of hydrogen bond donor promotes the deposition of Zn element by decreasing the concentration of [ZnCl4]2− and increasing the concentration and mobility of Zn2+ in electrochemical double layer. Consequently, the addition of C7H6O6S narrows the deposition potential gap of S and Zn elements in the range of −1.0 to −1.2V, thus resulting in their co-deposition to form pure ZnS. [Copyright &y& Elsevier]

Abstract: The effect of potassium hydrogen phthalate (C8H5KO4) as a special additive on the one-step electrodeposition of single-phase CuInS2 thin films from acidic solution (pH 2.5) was investigated in detail. The XRD, SEM and UV–vis–NIR characterization confirms that the addition of an adequate concentration of C8H5KO4 (23mM) to the electrolytic bath containing 12.5mM Cu2+, 10mM In3+, 40mM S2O3 2− and 100mM LiCl can contribute greatly to the controllable growth of pure chalcopyrite CuInS2 films with uniform surfaces and an ideal band gap of approximately 1.54eV. Complexation studies of C8H5KO4 with Cu2+ and In3+ in electrolytic solutions indicated that C8H5KO4 can complex Cu2+ more strongly than In3+ and move the electrode potentials of Cu2+ and In3+ near each other as determined by polarization analysis. Furthermore, the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) analysis performed in a series of solution systems revealed a three-step reaction mechanism for CuInS2 deposition and considerable adsorption of C8H5O4 − and Cu(C8H5O4)+ to the cathode surface. This deposition shows that the synergetic effects of complexation and adsorption originated from the additive on the Cu2+ electro-reduction, thus promoting the co-deposition of copper, indium and sulfur in the form of single-phase CuInS2. [Copyright &y& Elsevier]

Abstract: Highly graphitic carbon black (GCB) was synthesized by heat-treating commercial carbon black (CB, Vulcan XC-72) at 2800°C. The resulting GCB with a high degree of graphitization was analyzed by X-ray diffraction patterns (XRD), Raman spectroscopy and high-resolution transmission electron microscopy (HR-TEM) and was then used as the support material for synthesizing a platinum–GCB (Pt/GCB) hybrid catalyst. This catalyst was obtained through a simple chemical reduction using ethylene glycol as the reducing agent, which is amenable to large-scale production. The results show that the Pt nanoparticles are highly dispersed on the GCB with an average diameter of 3.6nm and a narrow particle size distribution. The electrochemical results obtained using cyclic voltammetry (CV), linear sweep voltammetry (LSV) utilizing a rotating disk electrode (RDE) and electrochemical impedance spectroscopy (EIS) show that the Pt/GCB electrocatalyst exhibits higher conductivity, stability, and electrocatalytic activity for the oxygen reduction reaction. The ORR proceeds through a four-electron process and when compared with Pt nanoparticles supported on Vulcan XC-72 (Pt/Vulcan XC-72) prepared under the same conditions, the Pt/GCB exhibits a significant enhancement for the ORR reaction. [Copyright &y& Elsevier]

A novel polypyrrole (PPy) coated three-dimensional (3D) SnO 2 nanotube arrays (SnO 2 @PPy) is synthesized via a template-assisted method followed by a chemical vapor-phase polymerization process as a high performance anode for lithium-ion batteries. In this new type electrode material, the hollow interiors of SnO 2 are able to provide enough spaces for the accommodation of large volume expansion during the insertion of lithium-ion, making for the improvement of the stability of electrode. Meanwhile, the addition of conductive PPy layer could facilitate the electron transport, prevent the aggregation of active materials and warrant the stability of as-formed solid electrolyte interface (SEI) films. As a result, the integration of 3D hybrid nanostructure electrode is capable of retaining a high capacity of 646 mA h g −1 after 150 cycles with a coulomb efficiency above 98% and a capacity retention of 221 mA h g −1 even at a high current density of 5000 mA g −1 , revealing better cycling and rate properties compared with bare SnO 2 nanotube arrays anode. This nanoengineering strategy can provide a facile and controllable way to synthesize other anode materials for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical reductive dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) in an aqueous solution was investigated at ambient temperature using a palladium/nickel foam (Pd/Ni foam) electrode in batch mode experiments. The catalytic electrode prepared using the standard chemical deposition method was further characterized using X-ray diffraction and scanning electron microscopy. It was observed that the reaction followed a pseudo-first-order kinetics model, the magnetic agitator-supported system could achieve 87% removal of 2,4-D within 4h, which is 16% higher than the efficiency obtained under a nitrogen atmosphere. No organic intermediates other than phenoxyacetic (PA), o-chlorophenoxyacetic acid (o-CPA) and p-chlorophenoxyacetic acid (p-CPA) were observed to be generated during the reaction. The dechlorination efficiency depended on several factors including the current density, the palladium loading and the initial concentrations of the supporting NaCl electrolyte and the 2,4-D. The palladium loading and the NaCl concentration had a greater effect on the dechlorination kinetics of 2,4-D. Furthermore, the efficiencies of dechlorination and PA formation could be improved by optimizing the reaction system by modifying the ventilation conditions. [Copyright &y& Elsevier]

Abstract: This study investigated the electrochemical degradation of C.I. Reactive Red 195 (RR195) in aqueous solution on a Ti/SnO2–Sb/PbO2 electrode. The influence of operating variables on the mineralization efficiency was studied as a function of the current density, the initial pH, the initial concentration of the dye and the addition of NaCl. The efficiency of RR195 mineralization decreased with increased initial concentration, from 100mgL−1 to 400mgL−1. The current density had both a positive and a negative effect on degradation rates, and no significant effect of initial pH on RR195 mineralization was observed. Measurement of absorbance was used to discriminate the effect of NaCl in the electro-oxidation process. We found that the decolouring efficiency increased whereas the mineralization efficiency decreased with the increasing concentration of NaCl. The intermediates formed during the degradation were detected by gas chromatography–mass spectrometry, and the major aromatic intermediates identified were 1-(3,6,8-trihydroxy-1-naphthyl)urea, nitrobenzene, benzo-1,4-quinone, (3,6,8-trihydroxy-1-naphthyl)carbamic acid and phthalic acid. Quantitative measurement of organic and inorganic ions was done by ion chromatography. On the basis of the reaction products identified, a possible degradation pathway for the anodic oxidation of RR195 in aqueous solution is proposed. [Copyright &y& Elsevier]

This study accounts the controllable design over the structure and morphology of Ni-P nanomaterials directly growing on cellulose paper, and its excellent non-enzymatic electrocatalytic performance to urea. The Ni-P papers were prepared by simple solution soaking and electroless bathing. And the simple experimental steps and mild experimental conditions make it possible for large-scale industrial production, and potential for practical applications. In addition, tuning the pH and concentration of the electroless bath, the Ni-P nanomaterials with different morphologies of nanoflower, nanosheet, nanowire microsphere and microsphere were obtained. The Ni-P nanomaterials impart conductivity to cellulose paper while being potently sensitive to urea owing to its high catalytic activity. Cellulose paper has a large specific area and open macroporous framework which hadn't been damaged during the process of electroless bathing, providing much more activated sites for Ni-P deposition. And the prepared Ni-P papers, as composite materials of cellulose papers loading Ni-P nanomaterials, have high electrocatalytic properties to urea. Comparing the electrochemical behaviors of the four Ni-P paper electrodes with different morphologies, the Ni-P nanoflower paper electrode showed the best electrochemical performance with highest sensitivity of 683.46 μA mM−1 cm−2 in the low concentration range (0–1 mM) and 1140 μA mM−1 cm−2 in the high concentration range (1–11 mM), lowest detection limit of 12 μM, shortest response time of 3 s, which may owes to the highest surface area of the Ni-P nanoflower structure. It also has a good stability in room environment remaining 97% after 35 days of storage. Moreover, the electrocatalytic activities of the four Ni-P paper electrodes are ranked as follows: nanoflower > nanosheet > nanowire microsphere > microsphere. What's more, the long-term stability and repeatability, good selectivity of the flexible Ni-P paper make it successfully applied to swimming pool water quality monitoring. [ABSTRACT FROM AUTHOR]