Synthesis of High-Purity Sb Nanopowder Using Fine Sn Powder as a Reducing Agent

Antimony (Sb) nanopowder was synthesized using fine Sn powder as a reducing agent. The Sn powder was first produced by the chemical reduction of SnCl2·2H2O using commercial Al foil in acidic medium, yielding approximately 89% of the theoretical Sn yield. The resulting Sn powder exhibited a mean particle size of approximately 93 nm and a mean crystallite size of 57 nm, which promoted rapid reduction during Sb synthesis. Prior to synthesis, the composition of the Al foil was examined using SEM/EDS, confirming an Al-rich matrix containing minor Fe and Si impurities. High-purity Sb nanopowder was synthesized by reducing SbCl3 in acetone at 50 °C under magnetic stirring and ultrasonic agitation, using the produced fine Sn powder as a reducing agent, achieving approximately 97% of the theoretical yield. SEM analysis revealed nearly spherical particles of black Sb nanoscale powder with the most frequent size falling within the 20–40 nm range and a mean particle size of approximately 32 nm. XRD analysis confirmed a trigonal Sb structure with a mean crystallite size of around 23 nm. For comparison, pellets prepared from synthesized Sb nanopowder and commercial Sb powder were compacted and sintered under identical conditions. Vickers microhardness measurements showed that the hardness of the sintered Sb nanopowder pellet was approximately 62% higher than that of the commercial Sb pellet. In addition, UV-Vis-NIR reflectance measurements (240–840 nm) demonstrated that the reflectance of the Sb nanopowder pellet was approximately three times higher than that of the commercial Sb pellet. These results demonstrate that fine Sn powder can serve as an efficient reducing agent for the synthesis of high-purity Sb nanopowder with enhanced mechanical and optical properties.