Aqueous purpose-built nanostructured metal oxide thin films

Abstract

A novel concept in materials chemistry as well as an aqueous low-temperature thin film growth technique has been developed to create a new generation of smart and functional metal oxide thin film materials. These materials are modelled, designed and engineered to match the physical and structural requirements of their applications. This concept is well-sustained by a thermodynamic model monitoring the nucleation, growth and ageing processes through the chemical and electrostatic control of the interfacial free energy. It allows to monitor the size of nano and microparticles, their surface morphology and their orientation onto substrates as well as the ability to thermodynamically stabilize metastable crystal phases. This template- and surfactant-free aqueous chemical growth method allows generation of, at large scale and low-cost, advanced metal oxides nano- and micro-particulate multilayered thin films with complex architectures. It includes 3-dimensional highly oriented crystalline arrays of ferric oxides nanorods, zinc oxide nanorods, microrods, microtubes, and nanowires. Other applications include nanocomposite thin films consisting of chromium and iron sesquioxide and nanoporous ruthenium/ruthenium oxide thin film grown at low temperature from aqueous solution onto various substrates.