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

In 0 nanoparticles with tunable size are obtained via NaBH 4 -induced reduction of InCl 3 ·4H 2 O in diethylene glycol. Citrate-capping allows nucleating almost monodisperse and non-agglomerated In 0 nanoparticles. Effective size tuning is possible in a wide range (10–100 nm) just by varying the concentration of NaBH 4, resulting in mean diameters of 8, 55, and 105 nm. The citrate-capped In 0 nanoparticles, moreover, turn out as surprisingly stable against air oxidation. According to XRD and SEM analysis, the 8 nm-sized In 0 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 In 0 particles.