Solution combustion synthesis of metal nanopowders: Nickel—Reaction pathways

Abstract

Wiley Online Library (wileyonlinelibrary.com).Nanopowders of pure nickel were directly synthesized for the first time by conventional solution combustion synthesis (SCS) method. In this article, a specific reaction pathway is suggested to describe the metallic phase formation during SCS. It is proposed that the exothermic reaction between NH 3 and HNO 3 species formed during the decomposition of glycine and nickel nitrate acts as the source of energy required to achieve the self-sustained reaction regime. A thermodynamic analysis of the combustion synthesis reaction indicates that increasing glycine concentration leads to establishing a hydrogen rich reducing environment in the combustion wave that in turn results in the formation of pure metals and metal alloys. TGA of reaction systems and XRD analysis of products in the quenched combustion wave show that the formation of oxide phases occurs in the reaction front, followed by gradual reduction of oxide to pure metallic phases in the postcombustion zone. A methodology for SCS of pure metals and metal alloys nanoparticles can be inferred from the results presented.

Synthesis of Ni nanoparticles with controllable magnetic properties by atmospheric pressure microplasma assisted process

“…10,11 However, these approaches are generally multisteps and time consuming, requiring pre/ posttreatments such as separation, washing or annealing to improve purity and crystallinity. Flexible control over composition, structure, and particle size during these processes is difficult to achieve, with the mechanisms poorly understood.…”

Single step synthesis of transition metal nanoparticles in aqueous phase for catalytic applications

“…Combustion synthesis (CS) techniques, being simple, quick and economic processes, are being used for synthesizing nanoparticles for various applications such as catalysis, drug delivery, magnetic materials etc [1][2][3][4][5][6][7][8]. These CS methods can be categorized in different groups on the basis of the nature of the reaction media as: (i) flame synthesis, (ii) heterogeneous condensed phase synthesis and (iii) solution-combustion synthesis (SCS).…”

“…These CS methods can be categorized in different groups on the basis of the nature of the reaction media as: (i) flame synthesis, (ii) heterogeneous condensed phase synthesis and (iii) solution-combustion synthesis (SCS). The SCS method uses water soluble precursor materials to make a homogeneous solution producing molecular level mixing, which results in a uniform product after combustion and provides an easy one step route for synthesizing metal/oxide nanoparticles [2,5,6,11]. The SCS method uses water soluble precursor materials to make a homogeneous solution producing molecular level mixing, which results in a uniform product after combustion and provides an easy one step route for synthesizing metal/oxide nanoparticles [2,5,6,11].…”

A 60-Second Microwave-Assisted Synthesis of Nickel Foam and Its Application to the Impregnation of Porous Scaffolds

“…Other authors 7 have suggested hydrogen coming from the glycine as the main reducing agent even though the pyrolysis of amino acids usually leads to NH 3 , CO 2 and water. 15 The ratio of glycine to nitrate ions is of great relevance as the lean fuel compositions do not ignite and other glycine rich stoichiometries do not provide the vigorous reaction to produce the metal phase.…”

“…The synthesis of metallic nickel by combustion synthesis has been reported to take place in a hot-plate 6 and an insight into the reaction mechanism has been given before. 7 Previous reports indicate the production of nickel metal by irradiating with microwaves a mixture of nickel nitrate and an organic fuel [8][9][10] with reaction times up to 10 minutes. Here, we take the experiments further by simplifying and speeding up the synthesis and using it as a processing technique with great potential to produce anodes for fuel cells.…”