Preparation, characterization and application in cobalt ion adsorption using nanoparticle films of hybrid copper–nickel hexacyanoferrate

Abstract

Different mole ratios (n Cu : n Ni ¼ x : y) of hybrid copper-nickel metal hexacyanoferrates (Cu x Ni y HCFs) were prepared to explore their morphologies, structure, electrochemical properties and the feasibility of electrochemical adsorption of cobalt ions. Cyclic voltammetry (CV), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated that the x : y ratio of Cu x Ni y HCF nanoparticles can be easily controlled as designed using a wet chemical coprecipitation method. The crystallite size and formal potential of Cu x Ni y HCF films showed an insignificant change when 0 # x : y < 0.3. Given the shape of the CV curves, this might be due to Cu 2+ ions being inserted into the NiHCF framework as countercations to maintain the electrical neutrality of the structure. On the other hand, crystallite size depended linearly on the x : y ratio when x : y > 0.3. This is because Cu tended to replace Ni sites in the lattice structure at higher molar ratios of x : y. Cu x Ni y HCF films inherited good electrochemical reversibility from the CuHCFs, in view of the cyclic voltammograms; in particular, Cu 1 Ni 2 HCF exhibited long-term cycling stability and high surface coverage. The adsorption of Co 2+ fitted the Langmuir isotherm model well, and the kinetic data can be well described by a pseudo-second order model, which may imply that Co 2+ adsorption is controlled by chemical adsorption. The diffusion process was dominated by both intraparticle diffusion and surface diffusion. Fig. 7 (a, b and c) CV of Cu x Ni y HCF films in 0.5 M Co 2+ solutions at different scan rates (v ¼ 0.005, 0.025, 0.05, 0.1, 0.15 V s À1 ); insets show the logarithmic values of reduction peak current (i pc ) as a function of the logarithmic values of scan rate; (d) Nyquist plots of Cu x Ni y HCF films from 100 Hz to 1000 kHz.This journal is

Removal of Cd(II) from Micro-Polluted Water by Magnetic Core-Shell Fe3O4@Prussian Blue

“…Similar peaks of Fe 3 O 4 and Fe 3 O 4 @PB at 2 θ 18.29, 30.14, 35.49, 37.14, 43.13, 53.52, 57.04, and 62.64° were indexed as (111), (220), (311), (222), (400), (422), (511), and (440) planes, respectively, well-matched with the previous researches [ 42 , 43 ]. Besides, Fe 3 O 4 @PB displays four predominant 2θ peaks compared with Fe 3 O 4 in the range of 17–40° corresponding to the Bragg planes of (200), (220), (400), and (420) [ 44 ], which belong to the face-centered cubic lattice structure of PB. These prove that the composites are designed by the synergistic effect between PB shell and Fe 3 O 4 core, and the introduction of Fe 3 O 4 did not affect the crystallinity of PB nanoparticles.…”

Review—Prussian Blue and Its Analogs as Appealing Materials for Electrochemical Sensing and Biosensing

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“…79 Bimetallic PBA.-Future developments in the field shall be carried out by synthesizing novel PBA having two metals in the outercoordination sphere. Some current examples are Ni-Fe, 80 Co-Ni, 81 Cu-Ni, 53 Cu-Zn, 82 Cu-Co, 83 Zn-Ni, 84 Mn-Fe, 85 or Co-Mn. 55,86 Bimetallic PBA have an excellent electrochemical behavior due to their enhanced stability in alkaline solution and distinctive cation permeability.…”

Unidirectional Current in Layered Metal Hexacyanometallate Thin Films: Implication for Alternative Wet-Processed Electronic Materials

“…Films were also prepared with combinations of different M 1 -HCM 2 materials. Tan and co-workers studied films containing Cu x Ni y -HCF with different stoichiometries of Cu and Ni, which was easily tuned by the reactant molar ratio. Electrochemical responses of Cu x Ni y -HCF show the redox features of the Ni-HCF and Cu-HCF films.…”

“…39,44 Films were also prepared with combinations of different M 1 -HCM 2 materials. Tan and co-workers 45 Different M 1 -HCM 2 materials can also be combined as stratified layers. Such a layered system has been used to modify electrodes so that they can sustain only a unidirectional current flow.…”