Synthesis of Cobalt-Nickel Nanoparticles via a Liquid-Phase Reduction Process

Abstract

Cobalt-nickel nanoparticles (Co-Ni-NPs) show promising electrochemical performance in oxygen and hydrogen evolution reactions (OER and HER) due to their physicochemical properties such as electronic configuration and great electrochemical stability. Therefore, developing new economically and environmentally friendly methods of synthesizing Co-Ni-NPs has become a practical requirement. Co-Ni-NPs were produced by employing the liquid-phase reduction method. Nickel and cobalt sulfate solutions in hydrazine monohydrate with various mixing ratios were used as raw materials. Nickel plays an important role in the nucleation process via increasing the reduction reaction rate throughout the formation of Co-Ni-NPs. Furthermore, the acceleration of the Co-Ni-NPs formation process may be attributed to the partial dissolution of Ni(OH)2 in the presence of N2H4 and/or citrate-anions and the formation of the Ni-N2H4 or Ni-Cit complexes in contrast to Co(OH)2.

The delicate balance of phase speciation in bimetallic nickel cobalt nanoparticles

“…While there are many reports of supported NiCo NPs, 5,[12][13][14][15] synthetic path in one pot using colloidal routes seems more difficult to design. These can take advantage of the different reduction potential of Ni and Co, [16][17][18][19][20][21][22][23][24] of electroless deposition, 25 or of laser ablation 26 although they may end up being fairly aggregated 27 or poorly crystallized, 19 or too crystallized to be attributed to nano-domains. 28 Few reports mention the possibility to form composition-controlled NiCo NPs.…”

Fabrication of a Co-Ni/TiO2 Core-Shell Sensor for Label-Free Quantification of Human Serum Albumin in Hepatitis C Virus Patients

“…The obtained Co-Ni precipitates were washed with ethanol and distilled water and dried in a vacuum dryer. 28 Fabrication of Co-Ni/TiO 2 nanocore shells.-The precipitation method was used for coating, and quantities of synthesized TiO 2 and Co-Ni powder (suspended in 50 ml DMSO) were adjusted to 1.5 g and 1.8 g, respectively. The mixture was shaken for 30 min to obtain a homogeneous solution, and 1 M sodium hydroxide was added dropwise to maintain pH at 9.…”

Physicochemical Analysis and Magnetic Properties of Nickel Cobalt Oxide (NiCo2 O 4 ) Using Self-Combustion Method with Solvent Variation as Supercapacitor Materials

“…A number of metal oxides, such as RuO2, NiO, MnO2, Co3O4, and NiCo2O4, have been reported as the auspicious supercapacitor due to their high specific capacitance, great cyclic stability, low cost, and environmentally friendly. Therefore, the nanoparticles of metal oxide present more excellent physical and chemical properties than the same material in greater size, such as the mechanical, electrical, magnetic, and optical power 2 . The NiCo2O4 is generally perceived as a mixed valence oxide that adopts the pure spinel structure, in which the nickel stays at the octahedral and cobalt sites distributed in both octahedral and tetrahedral sites, applicable for various fields, such as the electrochromic film, fuel cell catalyst, sensor gas, cathode electrode of the battery, magnetic material, photovoltaic, electrochemical supercapacitor and color sensitive photocathode.…”