The influence of current density and bath temperature on electrodeposition of rhodium film from sulfate–phosphate aqueous solutions
01 Oct 2019-Journal of Applied Electrochemistry (Springer Netherlands)-Vol. 49, Iss: 10, pp 1043-1054
TL;DR: In this article, the influence of current density and bath temperature on phases, crystal structure, microstructure, and deposition rate of rhodium films was studied by X-ray diffraction and scanning electron microscopy, respectively.
Abstract: Rhodium films were electrodeposited galvanostatically on copper–zinc alloy substrates from sulfate–phosphate aqueous solutions, in order to obtain a smooth, dense, and thick Rh film for electrical contacts. The influence of current density and bath temperature on phases, crystal structure, microstructure, and deposition rate of the film was studied. The phases and crystal structure, as well as microstructure of the film were determined by X-ray diffraction and scanning electron microscopy, respectively. The results showed that the current density and bath temperature had a significant influence on electrodeposition of rhodium film. The particles or aggregates on the surface evolved from fine to coarse and large with the increase of current density and bath temperature. By adjusting the deposition conditions, the optimized current density and bath temperature were 6.4–12.7 mA cm−2 and 50 °C, respectively. The film was composed of polycrystalline phase with monometallic form. The film was uniform and dense at low current density. The thickness of the film was up to 1.38–2.1 μm. At the optimal temperature of 50 °C, the surface of the film was smooth and fine. At the same time, the electrodeposition mechanism of the film was discussed. Rhodium films were electrodeposited from sulfate–phosphate aqueous solutions. The influence of current density and bath temperature on electrodeposition of the film was studied, and at the same time, the electrodeposition mechanism of the film was addressed.
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TL;DR: In this paper, iridium-cobalt (Ir-Co) thin films were galvanostatically electrodeposited on a copper (Cu) foam electrode as an electrocatalyst for water splitting in 1.0 M KOH alkaline medium.
34 citations
TL;DR: In this article, Nanocrystalline nickel coatings were electroplated from a Watts-type bath with the addition of H3BO3 ranging of 5-25g·L−1, and the microstructure, texture and grain size of the coatings deposited with different HBO3 contents for different plating times were characterized by optical microscopy, scanning electron microscopy and X-ray diffraction.
Abstract: Nanocrystalline nickel coatings were electroplated from a Watts-type bath with the addition of H3BO3 ranging of 5–25 g·L−1. In order to study the evolution of preferential orientation of Ni electrodeposits, the microstructure, texture and grain size of the coatings deposited with different H3BO3 contents for different plating times were characterized by optical microscopy, scanning electron microscopy and X-ray diffraction, further the residual stress, microhardness, and abrasion resistance of the texture-oriented coatings were measured by X-ray diffraction, Vickers microhardness tester, and Calotester, respectively. The electrochemical corrosion resistance of the highly texture-oriented coatings and the substrate was evaluated by polarization and electrochemical impedance spectroscopy. The results show the preferential orientation of the coating was gradually changed from (200) to (220) crystal plane with increasing H3BO3 content after plating time of 1 h. The longer the plating time was applied, the higher the degree of Ni (200) orientation was produced at a low H3BO3 concentration of 5 g·L−1. The preferential orientation of the coatings at a high H3BO3 concentration of 25 g·L−1 was changed initially from (111) + (200) to (200) plane, then random orientation, and evolved to (220) plane after plating time of more than 20 min. The stability of various textures of Ni electrodeposits against plating time-H3BO3 concentration was established, and at the same time the microstructure-property relationship was developed. The average grain size of nickel coating was about 50–65 nm. The average residual stresses of the coatings with (200), (200) + (220) and (220) orientations were −64.3 ± 5 MPa, −477.2 ± 57 MPa and −618.0 ± 36 MPa, respectively. The microhardness of the coating increased gradually from 242.52 ± 10HV1 to 269.46 ± 12HV1 with increasing H3BO3 content because of the inverse Hall-Petch and grain orientation. The abrasion and corrosion resistances of (200)-oriented coatings were better than those of (220)-oriented coatings.
22 citations
TL;DR: In this paper, an as-deposited iridium-nickel (Ir-Ni) thin film was used as an electrocatalyst for hydrogen evolution reaction (HER) in an electrolyte containing 13.5 m sodium hexabromidate(III) and 40.5m Ni sulphate hexahydrate.
Abstract: Iridium–nickel (Ir–Ni) film is of great interest for catalytic and corrosive environment applications. Ir–Ni thin films as an electrocatalyst for hydrogen evolution reaction (HER) were galvanostatically electrodeposited on copper (Cu) foam from an electrolyte containing 13.5 mM sodium hexabromoiridate(III) and 40.5 mM Ni sulphate hexahydrate, simultaneously compared with electrodeposited Ir and Ni thin films. The top surface morphology of the film was characterized by scanning electron microscopy. The chemical composition of the film was determined by energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. The electrocatalytic performance was performed by linear sweep voltammogram and cyclic voltammetry. The results showed that Ir–Ni thin film adhered to Cu foam and the surface appeared much rougher than the surface of Ni film. The chemical composition of Ir in the deposit was 80 ± 1.2 at.%. The film was composed of nanograins. The top surface of as-deposited film was mainly composed of metallic state. However, the top surface of the film consisted of oxides states, such as Ni oxides or Ni(OH)2, and Ir oxides after electrochemical measurements. As-deposited Ir–Ni thin film with large real active area exhibited high efficient electrocatalytic activity for HER, and achieved a current density of 10 mA cm2 at an overpotential of 60 mV and a Tafel slope of 40 mV dec−1, which is superior to pure Ir and Ni thin films. The remarkable increase in electrocatalytic activity for Ir–Ni film was ascribed to both increased surface area of active centers due to relatively rough and electrocatalytic synergism of Ir and Ni for the HER. Ir–Ni thin film electrodeposited on a foam copper electrode was used as an electrocatalyst for HER. The surface of as-deposited film was composed of metallic state. As-deposited Ir–Ni thin film with large real active area exhibited high efficient electrocatalytic activity for HER, and achieved a current density of 10 mA cm2 at an overpotential of 60 mV and a Tafel slope of 40 mV dec−1, which is superior to pure iridium and Ni thin films. As-deposited film possessed a good stability by accelerated degradation studies.
8 citations
TL;DR: In this paper, a small amount of graphene oxide was incorporated into a succinimide silver-plating system in Hull-cell alkaline solutions by the addition of 0.4 g L−1 graphene oxide.
Abstract: Silver is electroplated on the surface of connectors as a protective barrier layer in order to improve the corrosion resistance and to increase the durability of the connector. In this work, silver-graphene films were electrodeposited on copper–zinc alloy substrates from a succinimide silver-plating system in Hull-cell alkaline solutions by the addition of 0.4 g L–1 graphene oxide. The crystallographic structure and microstructure of the formed films were determined by X-ray diffraction and scanning electron microscopy, respectively. The corrosion resistance of the films was measured by a potentiodynamic polarization test. The results show that a low amount of graphene was incorporated into a silver deposit. The addition of graphene oxide could not influence the deposition rate and the crystallographic structure of the film, but resulted in a decrease in the size of aggregates or particles, compared with those of a pure silver film. The optimal current density was found to be 0.5 ~ 1.0 A dm–2, the surface of the films had a homogeneous close-packed fine-crystalline structure. The films were uniform, dense, and adherent to the substrate, without any evidence of delamination. At the same time, the addition of graphene oxide improved the corrosion resistance of silver films to a certain extent.
3 citations
References
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TL;DR: In this article, the effects of organic additives, bath temperature, and pH on the nanostructure of nano-copper were investigated for nano-Pd and they demonstrated how the shape of the current pulses influenced the grain size.
Abstract: The nanostructure of nano-metals prepared by pulsed electrodeposition is to a large extent adjustable by the appropriate choice of physical and chemical parameters of the electrolysis. For nano-Pd we have demonstrated recently how the shape of the current pulses influences the grain size. Here we focus on the effects of organic additives, bath temperature, and pH on the nanostructure of nano-copper.
214 citations
01 Jan 2008
TL;DR: In this article, the authors reviewed the process of electrodeposition, and its place in the general context of electrode reactions and charge transfer across the metal/solution interface is set.
Abstract: In this section, the process of electrodeposition is reviewed briefly, and its place in the general context of electrode reactions and charge transfer across the metal/solution interface is set (Section 1.1). In Section 1.2, special emphasis is given to deposition of alloys, and particularly to anomalous deposition of alloys (Sections 1.2.3 and 1.2.4). Next, the phenomenon of induced codeposition is defined, and possible mechanisms are discussed briefly (Section 1.2.5). Several electroless (Section 1.2.6) and electrodeposition processes, in which induced codeposition plays a role, are mentioned. A more extensive discussion of electrodeposition of W-, Moand Re-based alloys is included in Section 2. Typical
133 citations
Book•
21 Feb 2011
TL;DR: In this article, the authors discuss the potentials of PHASES in ELECTROCHEMISTRY, including under-potential de-position and single-and multiple-step reactions.
Abstract: 1 INTRODUCTION 2 THE POTENTIALS OF PHASES 3 FUNDAMENTAL MEASUREMENTS IN ELECTROCHEMISTRY 4 ELECTRODE KINETICS: SOME BASIC CONCEPTS 5 SINGLE-STEP ELECTRODE REACTIONS 6 MULTI-STEP ELECTRODE REACTIONS 7 SOME SPECIFIC EXAMPLES 8 THE IONIC DOUBLE-LAYER CAPACITANCE Cdl 9 ELECTROCAPILLARITY 10 NANOTECHNOLOGY AND ELECTROCATALYSIS 11 INTERMEDIATES IN ELECTRODE REACTIONS 12 UNDERPOTENTIAL DEPOSITION AND SINGLE-CRYSTAL ELECTROCHEMISTRY 13 ELECTROSORPTION 14 EXPERIMENTAL TECHNIQUES: 15 EXPERIMENTAL TECHNIQUES (2) 16 EXPERIMENTAL TECHNIQUES (3) 17 THE ELECTROCHEMICAL QUARTZ-CRYSTAL MICROBALANCE 18 CORROSION 19 ELECTROPLATING 20 ENERGY CONVERSION AND STORAGE
113 citations
TL;DR: In this paper, a procedure for the constant potential electrodeposition of rhodium onto nickel electrodes, the subsequent surface characterizations, and electrochemical evaluation is presented, and the resulting Ni/Rh electrodes were evaluated for their activity as anode catalysts for the electro-oxidation of urea.
Abstract: A procedure for the constant potential electrodeposition of rhodium onto nickel electrodes, the subsequent surface characterizations, and electrochemical evaluation is presented. The resulting Ni/Rh electrodes were evaluated for their activity as anode catalysts for the electro-oxidation of urea. A detailed procedure for the electrodeposition of Rh onto Ni foil is provided. It is shown that the electrocatalytic performance of Ni/Rh electrodes on the oxidation of urea in alkaline medium is primarily influenced by two electrodeposition parameters: the applied electrodeposition potential and the loading of Rh (mg cm−2). An optimization for electrocatalytic performance based on the electrodeposition potential and Rh loading is demonstrated. The effect of these parameters on visual finish, surface morphology, and crystal structure was also studied.
109 citations