Shape-controlled synthesis of silver crystals mediated by imidazolium-based ionic liquids

Abstract

This work presents an approach toward the shape-controlled synthesis of Ag crystals with hierarchical structures by exploitation of ionic liquids (ILs) as a shape-regulating agent. The synthesis of Ag crystals involves the reduction of AgNO(3) by EG in the presence of ILs, specifically 1-butyl-3-methylimidazolium methylsulfate (bmim-MeSO(4)). In accordance with non-classical crystallization growth mechanism, the primary Ag nanoparticles were formed at the early stage of the reaction, and then self-organized into 1D or 3D Ag superstructures via an IL-mediated self-assembly process. Their final morphologies were strongly dependent on the reaction conditions such as the concentration of ILs in the reaction mixture and the reaction temperature, which suggests that ILs play an important role in controlling the shape of the Ag crystals.

Fast track to nanomaterials: microwave assisted synthesis in ionic liquid media

“…The synthesis of silver nanoparticles in n-Bu 4 POAc yields small and uniformly shaped particles which show a bimodal diameter distribution with a major maximum at 6.7 nm (AE0.1 nm) and a minor maximum at 15.6 nm (AE0.8 nm) (Fig. 3).…”

“…45,46 This can be attributed to the partial charge of the metal particles surface which is benecial for coulomb interactions between the particle and the polar IL (electrosteric shielding). 47,48 Microwave synthesis of NiO and ZnO nanoparticles NiO-and ZnO-nanoparticles could be obtained both in n-Bu 4 POAc from nickel carbonate hexahydrate (NiCO 3 $6H 2 O) and zinc carbonate (ZnCO 3 ), and in bmmim NTf 2 from zinc acetate dihydrate (Zn(OAc) 2 $2H 2 O). Due to a better dispersibility of nickel acetate in 1-butyl-3-methylimidazolium N,N-bis(triuoromethylsulfonyl)imid (bmim NTf 2 ), the NiO particles are synthesised in the latter.…”

“…These nanoparticles are very homogeneously distributed and show no agglomerated sites. The silver nanoparticles obtained in n-Bu 4 Obviously, the use of different ionic liquids strongly inu-ences the growth of the nanoparticles. n-Bu 4 POAc is a very polar ionic liquid with low melting point (mp ¼ 55 C); contrary bmmim NTf 2 is a room temperature ionic liquid (mp ¼ À4 C) with a relatively low polarity.…”

“…Microwave synthesis of Cu(0)-and Ag(0)-nanoparticles Silver and copper nanoparticles were obtained both in n-Bu 4 POAc from silver carbonate (Ag 2 CO 3 ) and copper carbonate (CuCO 3 ), respectively, and in bmmim NTf 2 from silver acetate (AgOAc) and copper acetate monohydrate (Cu(OAc) 2 $H 2 O). The syntheses were conducted under microwave heating.…”

“…Accordingly, ionic liquids are very popular concerning the synthesis of zero-and one-dimensional nanostructures. [4][5][6][7] Ionic liquids can act as solvents, cosolvents, [8][9][10][11] promoters, 12,13 reducing agents, [12][13][14][15] capping or protective agents and surfactants. 3,16 Despite their low melting points, ionic liquid phases show structural properties of lower order: they consist of polar and nonpolar nanoscale regimes which make them ideal templates for nanoscale synthesis.…”