Novel Microwave-Assisted Synthesis of Nickel/Carbon (Ni/C) Nanocomposite with Tannin as the Carbon Source

Abstract

Metal/carbon nanocomposites find use in many potential applications, in areas such as batteries, catalysts, inks, polymer additives, and solar cells. Nickel/carbon nanocomposites are widely used as heterogeneous catalysts in oil processing and other catalytic reactions. Here we describe a novel microwave-assisted synthesis of nickel/carbon nanocomposites, achieved within a few minutes, starting from nickel salts and a renewable high-content carbon source, tannin. The carbon precursor is Quebracho tannin, which is a renewable-resource material obtained from the hot-water extraction of Schinopsis lorentzii and Schinopsis balansae, which are indigenous to Argentina and Paraguay. The process involves a simultaneous carbonization of the carbon precursor as well as the reduction of nickel ions to elemental nickel nanoparticles in an ambient atmosphere. Thus, this technique provides a fast, easy, and economical way to produce nickel/carbon nanocomposites without requiring the need for hydrogen or inert gas during the transformation. This technique could be used to synthesize a wide range of other metal/carbon nanocomposites and therefore holds tremendous economic promise. The nanocomposites have a high surface area and may be suitable as high efficiency catalysts.