One-Pot Synthesis of In⁰Nanoparticles with Tuned Particle Size and High Oxidation Stability

Abstract

In0 nanoparticles with tunable size are obtained via NaBH4-induced reduction of InCl3·4H2O in diethylene glycol. Citrate-capping allows nucleating almost monodisperse and non-agglomerated In0 nanoparticles. Effective size tuning is possible in a wide range (10–100 nm) just by varying the concentration of NaBH4, resulting in mean diameters of 8, 55, and 105 nm. The citrate-capped In0 nanoparticles, moreover, turn out as surprisingly stable against air oxidation. According to XRD and SEM analysis, the 8 nm-sized In0 particles are molten at room temperature. Size-dependent evolution of the plasmon resonance is observed and results in a brownish-red color and a distinct absorption in the case of the smallest In0 particles.

Metallic indium spheres by the anaerobic ethanol oxidation of indium oxide

“…Reducing metals of Zn, Sn, and Na have values of 9.4, 7.3, and 5.1 eV, respectively [6]. Metallic In particles or nanoparticles (NPs) are prepared using several methods, which include a reduction method [7], decomposition of an In complex [4], and vapor/sputter deposition method [8,9]. Recently, Dorn et al used [11].…”

“…Metallic NPs were characterized by UV-visible absorption and XRD. In NPs could be stabilized by citratecapping [7]. The surface plasmon resonance peak of In NPs were reported to be dependent on the particle size, e.g., 280 and 264 nm absorption peaks for 105 and 8 nm sizes, respectively [7].…”

“…In NPs could be stabilized by citratecapping [7]. The surface plasmon resonance peak of In NPs were reported to be dependent on the particle size, e.g., 280 and 264 nm absorption peaks for 105 and 8 nm sizes, respectively [7]. Singh et al reported In NPs with sizes less than 20 nm (surface plasmon resonance at 238m) prepared by the reduction of InCl 3 in a NaBH 4 methanolic solution at 70°C [12].…”

Synthesis of indium nanoparticles at ambient temperature; simultaneous phase transfer and ripening

“…Due to the diverse application of indium nanoparticles, their synthesis with different size distributions and morphologies has been reported using various methods, such as the reduction of indium salts with NaBH 4 (Chou et al 2008; Hammarberg and Feldmann 2009; Kind and Feldmann 2011; George et al 2015), LiBH 4 (Lim et al 2010), sodium metal (Khanna et al 2005) or alkalides and electrides (Tsai and Dye 1991). These reduction approaches at high temperatures result in a highly size-monodisperse spherical nanoparticles.…”

“…In a two-step synthesis approach, the indium nanoparticles, initially synthesised by NaBH 4 reduction of InCl 3 .4H 2 O in diethylene glycol at 100 °C, were transferred to a non-polar medium via oleylamine (particle diameters between 10 and 12 nm) (Hammarberg and Feldmann 2009). The synthesis of size-tunable (mean diameters between 8 and 105 nm), air stable, citrate-capped indium nanoparticles, via NaBH 4 reduction of InCl 3 .4H 2 O in diethylene glycol at 100 °C is another example of high-temperature synthesis (Kind and Feldmann 2011). Furthermore, sub-10 nm spherical indium nanoparticles with uniform size and shape, capped with oleylamine, trioctylphosphine (TOP) or trioctylphosphine oxide (TOPO) have been synthesised by LiBH 4 reduction of InCl 3 under reflux conditions in isobutylamine (Lim et al 2010).…”