Electrocatalytic Activity of Galvanostatically Deposited Ni Thin Films for Methanol Electrooxidation

Abstract

Nickel and nickel‐based nanomaterials are an attractive choice to replace noble metals as electrocatalysts in alkaline direct alcohol fuel cells (ADAFCs) owing to their lower cost and suitable electrocatalytic activity. Among the different synthetic methods available for the production of nanostructured materials, galvanostatic electrodeposition offers a fast and simple means of fabricating active electrodes. Therefore, thin‐layers of nickel were electrodeposited onto polycrystalline gold electrodes using constant current pulses from an electrolyte containing 50 mM NiSO4. Combined effects of current density pulse and the presence of sulfate or chloride anions in the supporting electrolyte on the electrocatalytic activity of the deposited nickel nanostructures were studied. The surface concentration of Ni(OH)2 in alkaline medium, evaluated through cyclic voltammetry in 0.5M methanol + 1M KOH, was used as a performance parameter together with the electrocatalytic intensity, EI, defined as the sum of forward and reverse currents densities in methanol electro‐oxidation. It was found that highest electrocatalytic activities were obtained when using current density pulses close to 4.0 × 10−3A cm−2 in the presence of sulfates, which leads to a strong correlation between the electrocatalytic activity for the oxidation of methanol and the surface concentration of Ni(OH)2, displaying better properties than their chloride counterparts.

Galvanostatically Deposited PtNi Thin‐Films as Electrocatalysts for the Hydrogen Evolution Reaction

“…Applying a potential pulse of −1.259 V versus RHE would result in the formation of a 1 to 2 nm thick Ni layer, depending on the Ni 2+ concentration of the platting bath. Recently Salinas‐Quezada et al [25] . showed that galvanostatic electrodeposition on Ni on Au also leads to the formation of Ni thin‐layers.…”

“…Our group previously used single-pulse galvanostatic electrodeposition to generate Ni thin-layers on a Au electrode; the Ni deposits exhibit high catalytic activity for methanol electro-oxidation. [25] The same methodology can be used to obtain NiMo deposits with HER activity in acidic media. [26] Herein we report a systematic study on the influence of the applied current density on the PtNi deposit's activity and surface composition for HER in alkaline media.…”

“…In contrast, electrochemical deposition is a fast and straightforward method that allows high control over the deposits’ morphology. Our group previously used single‐pulse galvanostatic electrodeposition to generate Ni thin‐layers on a Au electrode; the Ni deposits exhibit high catalytic activity for methanol electro‐oxidation [25] . The same methodology can be used to obtain NiMo deposits with HER activity in acidic media [26] .…”

Effect of copper doping on the photocatalytic performance of Ni2O3@PC membrane composites in norfloxacin degradation

“…Ni-based nanocomposites possess great prospects for practical applications, particularly in water purification processes. Electrochemically deposited Ni nanotubes on various supports been intensively studied, 25 demonstrating their potential in catalytic, 26,27 biomedical 28,29 and sensors 30 applications. The electroless deposition technique has also been applied for synthesis of hollow nickel or nickel oxide nanotube arrays, highlighting their excellent catalytic and conductive properties.…”

Study of Methanol Electro-Oxidation on Thin Nickel Films by Sampled Current Voltammetry

“…Because of the potential applications of ADMFC, many works have focused on the synthesis of materials with electrocatalytic activity comparable to that of platinum. Salinas et al (6) showed that Ni films deposited on Au under galvanostatic control had a high electrocatalytic activity compared to similar material synthesized by more expensive and time-consuming methods. In this work, Ni films were deposited by the galvanostatic method on polycrystalline gold electrodes.…”