Nonaqueous and surfactant-free synthesis routes to metal oxide nanoparticles

Nonaqueous sol-gel routes to metal oxide nanoparticles have become a promising alternative to aqueous methods, allowing the controlled synthesis of a variety of metal oxides as highly crystalline products at comparably low temperatures. The use of solvents like benzyl alcohol that also function as surface modifiers makes the addition of surfactants superfluous, resulting in improved product purity. In addition to a short overview of such nonaqueous routes to binary and ternary metal oxides, the facile synthesis of sodium and potassium niobates as well as of sodium tantalate and barium stannate nanoparticles via straightforward, surfactant-free pathways is reported.