Magnetite–Silica–Gold Nanocomposite: One-Pot Single-Step Synthesis and Its Application for Solvent-Free Oxidation of Benzyl Alcohol

Abstract

A simple and innovative method for a single-step–one-pot room temperature synthesis of magnetite–silica–gold nanocomposite has been demonstrated. This simple process involves a combination of different reactions occurring simultaneously. Specifically, coprecipitation of iron salts, reduction of gold chloride, and formation of silica, all at one instance, result in a unique nanocomposite of iron oxide, silica, and gold. The well-known method of coprecipitation of iron salts to form iron oxide nanoparticles has been modified suitably to include sodium silicate (silica source) instead of an alkali (for coprecipitation). Gold chloride premixed in sodium silicate, prior to reaction, gives the third and important functionality: gold nanoparticles, which can act as a catalyst. The nanocomposite so formed is stable due to the silica network, is magnetically separable, has high surface area, and is catalytically active. The composite has been characterized by a host of different techniques such as Fourier transfor...