Preparation and Electrochemical Properties of a Gallium-Doped Zinc Oxide Electrode Decorated with Densely Gathered Palladium Nanoparticles

Abstract

A novel method for chemically preparing densely gathered palladium nanoparticles (PdNPs) on a gallium-doped zinc oxide (GZO) electrode is reported. We found that PdCl42– could be captured directly on a bare GZO electrode surface simply by immersing a piece of GZO in an aqueous solution of K2PdCl4, resulting in a GZO electrode color change from transparent to yellow. The subsequent reduction of the composite electrode in an aqueous solution of NaBH4 produced a further color change to blackish-violet even after the PdCl42–-captured GZO had been washed and dried. X-ray photoelectron spectroscopy analysis confirmed the presence of Pd as PdCl42– and Pd0 on the GZO before and after reduction with NaBH4, respectively. The surface images collected using field emission scanning electronic microscopy revealed that the PdNPs were densely gathered and connected to one another. Although bare GZO electrodes have not been used extensively in voltammetric analysis, the present modification using densely gathered PdNPs shows promise as a new approach to constructing Pd-functionalized electrodes as confirmed by measuring voltammetric responses. The simple capture of metal complex precursors and nanostructuring followed by a simple reduction reaction on GZO is promising as a new and efficient fabrication method that conserves precious starting materials.

A Simple and Direct Preparation of a Substrate-Free Interconnected Nanostructured Carbon Electrode from Date Palm Leaflets for Detecting Hydroquinone

“…Figure B shows the corresponding plot of the anodic peak current as a function of the square root of the scan rate (Randles–Sevcik plot). The plot was linear over the full range of scan rates tested (R 2 =0.999), indicating that the reaction process was diffusion controlled …”

Linker-free chemical preparation of palladium nanoparticles on aluminum-doped zinc oxide electrodes for electrochemical water oxidation

“…Many efforts have been made to coat metals and their oxides on inexpensive substrates such as biomass-derived carbon materials and cheap metal oxide for electrocatalytic studies [10][11][12][13][14][15][16]. It is noted that transparent conducting oxides (TCOs) have been commonly used as the electrode substrate for electrochemical applications [17][18][19]. TCOs have excellent electrical conductivity and high optical transparency in the visible region of the electromagnetic spectrum.…”

“…TCOs have excellent electrical conductivity and high optical transparency in the visible region of the electromagnetic spectrum. They have been widely recorded for various electrochemical applications [17,18]. In particular, indium tin oxide (ITO), among the various types of TCOs, has mainly demonstrated excellent electrical and optical properties.…”

“…In particular, indium tin oxide (ITO), among the various types of TCOs, has mainly demonstrated excellent electrical and optical properties. Hence it is traditionally recognized to be an excellent solid substrate electrode for electrochemical water oxidation [18,[20][21][22][23][24][25]. However, ITO owns some disadvantages such as the high cost and inadequacy of indium production with it being the main raw material used in ITO preparation [17,18].…”

“…Hence it is traditionally recognized to be an excellent solid substrate electrode for electrochemical water oxidation [18,[20][21][22][23][24][25]. However, ITO owns some disadvantages such as the high cost and inadequacy of indium production with it being the main raw material used in ITO preparation [17,18]. Various alternative materials such as zinc oxide (ZnO) and conductive polymers have been suggested [17,18] to eliminate the inadequacy and cost issues.…”