Browsing by Subject "Electrodeposition"
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Item Open Access Complexing agent effect on the stoichiometric ratio of the electrochemically prepared CuInSe2 thin films(Elsevier, 2007) Beyhan, S.; Süzer, Şefik; Kadırgan, F.The electrodeposition of CuInSe2 is investigated to improve the stoichiometric properties of CuInSe2 layers on indium tin oxide (ITO)-coated glass substrates and to develop one-step electrodeposition method for solar cell applications. XPS was utilized for the characterization of the surface properties of CuInSe2 layers. The influence of the complexing agent, e.g. benzotriazole, bulk concentration of Cu and Se and deposition potentials on the stoichiometric properties, are discussed. © 2007 Elsevier B.V. All rights reserved.Item Open Access Continuous mesoporous pd films by electrochemical deposition in nonionic micellar solution(American Chemical Society, 2017) Iqbal, M.; Li C.; Wood, K.; Jiang B.; Takei, T.; Dag, Ö.; Baba, D.; Nugraha, A. S.; Asahi, T.; Whitten, A. E.; Hossain, M. S. A.; Malgras, V.; Yamauchi, Y.Mesoporous metals that combine catalytic activity and high surface area can provide more opportunities for electrochemical applications. Various synthetic methods, including hard and soft templating, have been developed to prepare mesoporous/nanoporous metals. Micelle assembly, typically involved in soft-templates, is flexible and convenient for such purposes. It is, however, difficult to control, and the ordering is significantly destroyed during the metal deposition process, which is detrimental when it comes to designing precisely mesostructured materials. In the present work, mesoporous Pd films were uniformly electrodeposited using a nonionic surfactant, triblock copolymer poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), as a pore-directing agent. The interaction between micelles and metal precursors greatly influences the metal growth and determines the final structure. The water-coordinated species interact with the ethylene oxide moiety of the micelles to effectively drive the Pd(II) species toward the working electrode surface. From small-angle neutron scattering data, it is found that spherical P123 micelles, with an average diameter of ∼14 nm, are formed in the electrolyte, and the addition of Pd ions does not significantly modify their structure, which is the essence of the micelle assembly approach. The uniformly sized mesopores are formed over the entire mesoporous Pd film and have an average pore diameter of 10.9 nm. Cross-sectional observation of the film also shows mesopores spanning continuously from the bottom to the top of the film. The crystallinity, crystal phase, and electronic coordination state of the Pd film are also confirmed. Through this study, it is found that the optimized surfactant concentration and applied deposition potential are the key factors to govern the formation of homogeneous and well-distributed pores over the entire film. Interestingly, the as-prepared mesoporous Pd films exhibit superior electrocatalytic activity toward the ethanol oxidation reaction by fully utilizing the accessible active surface area. Our approach combines electrochemistry with colloidal and coordination chemistry and is widely applicable to other promising metals and alloy electrocatalysts.Item Open Access Electrocatalytic hydrogen evolution with cobalt–poly (4-vinylpyridine) metallopolymers(Springer Netherlands, 2018) Kap, Zeynep; Ülker, Emine; Nune, Satya Vijaya Kuma; Karadaş, FerdiAbstract: A facile synthetic pathway using poly(4-vinylpyridine) as a polypyridyl platform is reported for the formation of a metallopolymer. Electrochemical studies indicate that the metallopolymer acts as an efficient H2 evolution catalyst similar to cobalt polypyridyl complexes. It is also observed that the metallopolymer is transformed to cobalt particles when a cathodic potential is applied in the presence of an acid. Electrochemical measurements indicate that an FTO electrode coated with these cobalt particles also acts as an efficient hydrogen evolution catalyst. Approximately 80 µmoles of H2 gas can be collected during 2 h of electrolysis at − 1.5 V (vs. Fc+/0) in the presence of 60 mM of acetic acid. A comprehensive study of the electrochemical and electrocatalytic behavior of cobalt-poly(4-vinylpyridine) is discussed in detail. Graphical Abstract: Poly(4-vinylpyridine) as a precursor for electrodeposited cobalt particles: a cobalt coat derived by a metallopolymer acts as an efficient H2 evolution catalyst. It can transform to a cobalt coat when a potential above − 1.1 V is applied in acid medium. Exchange current density of 10−2.67 mA cm−2 was observed from the Co-coat at − 1.5 V (vs. Fc+/0).Item Open Access Electrodeposited cobalt hexacyanoferrate electrode as a non-enzymatic glucose sensor under neutral conditions(Elsevier B.V., 2021-10-19) Oglou, Ramadan Chalil; Ghobadi, T. Gamze Ulusoy; Özbay, Ekmel; Karadaş, FerdiA CoFe Prussian blue analogue (CoFe PB) modified FTO electrode, prepared via a facile electrodepositionmethod, is investigated as a non-enzymatic glucose sensor under neutral conditions. The electrode ex-hibits a linear detection of glucose in the 0.1e8.2 mmol/L range with a detection limit of 67mM, asensitivity of 18.69mA/mM.cm2, and a fast response time of less than 7 s under neutral conditions. Its stability is confirmed with both electrochemical experiments and characterization studies performed on the pristine and post-mortem electrode. We also conducted a comprehensive electrochemical analysis to elucidate the identity of the active site and the glucose oxidation mechanism on the Prussian blue surface.Item Open Access Electron spectroscopic investigations of CdS and CdTe electrochemically coated on glass(Springer, 1996) Süzer, Ş.; Kutun, Ş.; Kadırgan, F.The electrodeposition of CdS and CdTe is investigated to improve the stoichiometric properties of CdS/CdTe layers on ITO-glass substrates for solar cell applications. X-ray photoelectron spectroscopy is utilized for the characterization of the CdS and CdTe layers. The influence of the electrodeposition potential, the pH and the thiosulfate concentration on the stoichiometry of CdS and CdTe layers are discussed. © Springer-Verlag 1996.Item Open Access Preparation and properties of electrodeposited Ni-B-V2O5 composite coatings(Elsevier, 2021-01-17) Waware, U. S.; Nazir, Roshan; Prasad, A.; Hamouda, A. M. S.; Pradhan, A. K.; Alshehri, M.; Syed, R.; Malik, A.; Alqahtan, M. S.Coatings of Ni-B have gained significant importance in various industries owing to their major role in improving mechanical properties including hardness, conductivity, and wear resistance. Despite all these characteristic features, there is still the need for a lot of modifications. This is to improve the properties of the coating so as to increase their durability and overall performance. The current study is based on development of Ni-B-V2O5 composite coating on mild steel substrate through the electrodeposition technique and the investigation of mechanical and anti-corrosive properties of the formed coating. The incorporation of V2O5 particles into the composite coating was confirmed by energy dispersive spectroscopy. X-ray diffraction pattern showed amorphous nature of electrodeposited Ni-B matrix, while the crystalline nature improved with the addition of V2O5 particles to the composite. Field emission scanning electron microscopy and atomic force microscopic studies clearly indicated that the addition of V2O5 particles to the Ni-B coating increased the surface roughness. Further studies reveal increase in the micro-hardness (by 171.11%), and elastic modulus (by 9.4%) in case of the Ni-B-V2O5 composite coating relative to the Ni-B coating. The enhanced micro-hardness was attributed to the inclusion of hard V2O5 particles into the Ni-B matrix, which in turn, may inhibit the dislocation motion in the composite. An increase in corrosion resistance (by 229%) was also experienced in the electrodeposited Ni-B-V2O5 composite coating in comparison to the bare Ni-B matrix, which may be due to the masking of inert V2O5 particles on the active region of the Ni-B composite.