Hydrothermal synthesis of Ir and Ir—Pd nanoparticles on carbon nanotubes

A technique for the formation of Ir and Ir—Pd nanoparticles on carbon nanotubes (CNTs) under hydrothermal conditions was proposed. Reduction of potassium hexachloroiridate(IV) from aqueous solutions with sodium tetrahydroborate in alkaline media at a temperature of 180 °C leads to the formation of iridium nanoparticles on the carbon material. Subsequently, the composite material Ir/CNT was modified by palladium deposition through the decomposition of an alkaline solution of tetraamminepalladium(II) chloride in an autoclave. The composition, dimensions, and structure of the obtained functional materials were characterized by scanning electron microscopy with local energy-dispersive X-ray fluorescence analysis, powder X-ray diffraction, and X-ray photoelectron spectroscopy. The metal particles uniformly coat on the CNTs and have diameters of 5–8 and 15–20 nm in the case of iridium and palladium, respectively.