A facile synthesis and characterization of surfactant (CTAB/TSC/TX-100) assisted Ir-Sn bimetallic nanoparticles

Abstract

The present work is mainly focused on the synthesis and characterization of surfactant-assisted Ir-Sn BMNP (bimetallic nanoparticles) using modified polyol method. CTAB (Cetyltrimethylammonium bromide), TSC (Trisodium citrate), and TX-100 (Triton X-100) as cationic, anionic, and nonionic surfactant respectively are used to study their effect on the particle size, morphology, and their stability. The synthesized particles are characterized by XRD, FE-SEM, EDAX, elemental mapping, TEM, HR-TEM, XPS and FT-IR, TGA, DTG, and DTA techniques. UV-Vis spectroscopy is used to monitor the synthesis of nanoparticles. The XRD patterns of all samples confirm that Ir-Sn BMNP are amorphous in nature. The influence of surfactant on the morphology and particle size of Ir-Sn BMNP samples was examined by the FE-SEM technique. The FE-SEM figures demonstrate that the particles of bimetal are in nano size, highly dispersed, and pseudo spherical in shape with smooth surfaces. The approximate crystallite (particle/grain) size of CTAB, TSC, and TX-100 assisted samples are ~1.39 nm (39 nm), ~2.2 nm (59 nm), and ~5.79 nm (89 nm) respectively, which are estimated from TEM and FE-SEM images. The presence and distribution of Ir and Sn elements in the BMNP is determined through EDAX and elemental mapping respectively. These techniques show that CTAB assisted Ir-Sn BMNP sample is in alloy form but TSC and TX-100 samples are in core-shell form, where the Ir core is surrounded by Sn shell. The XPS confirms the metallic state (Ir0), and the dual valence state of Sn (Sn2+ and Sn4+) is in the Sn 3d core level.