Instantaneous Synthesis of Stable Zerovalent Metal Nanoparticles under Standard Reaction Conditions

Abstract

In this report is discussed a novel, easy, and general synthesis method to prepare zerovalent iron (ZVI) and copper (ZV Cu) nanoparticles (NPs), from colloid dispersions in an environmental friendly organic solvent, ethylene glycol (EG). Conventional metallic salts are used as nanoparticle precursors; sodium borohydride (NaBH4) is the reducing agent, and triethylamine (TEA) is used as the nanoparticle stabilizer. The chemical changes take place instantaneously under normal reaction conditions. Small iron (alpha-Fe0 phase) and copper (fcc phase) NPs with average diameters of 10.2 +/- 3.3 and 9.5 +/- 2.5 nm, respectively, were obtained. In both cases, the experimental evidence reveals the absence of any metal oxide shell coating the particle surfaces, and their powders remain stable, under aerobic conditions at least for 3 weeks. ZVI NPs were characterized by X-RD, Mössbauer, and Raman spectroscopies and by EELS coupled to HR-TEM. Otherwise, copper NPs were characterized by X-RD, Z-contrast, and HR-TEM. This synthesis pathway is particularly suitable for large-scale and high-quality zerovalent metallic nanoparticle (ZV M NP) production due to its simple process and low cost.

New routes to Cu(i)/Cu nanocatalysts for the multicomponent click synthesis of 1,2,3-triazoles

“…36 In the case of monometallic Cu NPs, the prevailing structure-type noted has hitherto been Cu(core) @CuO/Cu 2 O(shell), 37 with efforts to control the formation of an oxide shell predicated on the use of capping agents that inhibit molecular access to the particle surface. [38][39][40] More recently, it has been shown that the use of polymeric capping agents may enhance the oxidative stability of NPs whilst permitting substrate access and efficient catalysis. 41 Moreover, the range of polymers available for stabilizing highly reactive main group nanomaterials has also very recently been extended through the use of poly(methyl methacrylate) (PMMA) to protect Mg nanocomposites.…”

Degradation of bis-p-nitrophenyl phosphate using zero-valent iron nanoparticles

“…Other characterizations of ZV iron NPs were published [17]. Table 1 summarizes the calculated parameters of the ZVI dispersion.…”

“…Table 1 summarizes the calculated parameters of the ZVI dispersion. These parameters were calculated considering the particle size distribution, assuming a completed reaction (excess of NaBH 4 was used) and spherical particles, see reference [17] for details. Parameters in Table 1 correspond to the ZVI NPs obtained in a typical synthesis as described in the Materials and Methods section.…”

“…The synthesis of ZV iron NPs in a previous work was published [17] and was carried out as follow: A 0.01078 g portion of FeBr 2 was dissolved in 15 mL of ethylene glycol under vigorous stirring and argon bubbling, at room temperature. Then, 0.01890 g of NaBH 4 was in situ dissolved in 8.75 mL of EG and simultaneously added to the reaction mixture.…”

The convenient preparation of stable aryl-coated zerovalent iron nanoparticles

“…A variety of different approaches have been employed to protect this sensitive material from oxidation, where commonly used methods include coating with carbon [19,22], silica [23], noble metals and oxides [24][25][26], or the utilization of different surfactants and stabilizers [27]. However, none of these approaches lead to covalent grafting.…”