Recent Developments on Molten Salt Synthesis of Inorganic Nanomaterials: A Review

A wide range of inorganic nanomaterials with many fascinating properties and application potentials in widespread fields may be synthesized by wet chemical synthetic routes. To achieve scientific and commercial viability of nanomaterials with uniformity and scalability, it is necessary to develop efficient and cost-effective, preferably sustainable, methods. The molten salt synthesis (MSS) method is one such bottom-up technique to fabricate a wide variety of inorganic nanomaterials with tunable size, morphology, and surface characteristics. It is also environmentally friendly, cost-effective, simple to operate, easy to scale, and generalizable, etc. This review gives a critical overview on this emerging and rapidly developing method for making defect free nanomaterials in well-defined texture, surface, and morphology at a relatively low formation temperature. We have discussed its different aspects, including the role of molten salts, the choice of molten salts, the electrochemical aspects, some advanced modifications of the conventional MSS technique, and their implications. To show the most recent development on MSS synthesized inorganic nanomaterials, this review only encompasses the studies reported over the last six years (2015–2020). We have summarized technologically important and emerging families of inorganic nanomaterials such as metal oxides, fluorides, nitrides, silicides, chalcogenides, oxohalides, borides, and carbides. Finally, a few perspectives for the MSS method are highlighted. It is expected that this review will further attract scientists to explore the MSS method in making size- and shape-tunable nanomaterials.