Very low temperature wet-chemistry colloidal routes for mono- and polymetallic nanosized crystalline inorganic compounds

The use of low temperature, sustainable processes based on cheap and safe chemicals as well as nontoxic, easy to handle chemicals and solvents is a challenging issue in modern inorganic chemistry; moreover the obtainment of crystalline functional nanostructures at low or even room temperature is the goal of many synthetic efforts. Within this framework, in these last years, we have developed in our group different room or low temperature (T < 150 °C) wet chemistry colloidal routes to prepare different inorganic functional nanomaterials. These compounds range from (1) ferrites to (2) pure and doped metal oxides, sulphides and halogenides, to (3) metal/metal oxide nanocomposites. The adopted wet chemistry routes encompassed (1) miniemulsions, (2) coprecipitation combined with hydrothermal route and (3) more classical colloidal routes, though revised in some critical aspects. This mini-review provides an overview of the main features as well as the pros and cons of the proposed routes for the obtainment of targeted inorganic systems for applications in optical bioimaging or in energy applications. It not only summarises already published work, but also presents some exciting perspectives disclosed by performed studies and past experience as well as comparisons with state-of-the-art research.