Green and cost-effective synthesis of the superconductor BSCCO (Bi-2212), using a natural deep eutectic solvent

Abstract Ionic liquids/Deep eutectic solvents have been extensively utilized in many different areas however, these systems have not been widely used for their chelating properties in the synthesis of phase pure metal oxides. This mainly due to the high cost of the ionic liquid and the lack of ability to solubilize some water-insoluble metal salts, such as bismuth nitrate. Here we present for the first time the use of a cost-effective natural deep eutectic solvent (NADES), namely betaine:D-(+)-glucose which is capable of solubilizing these insoluble metal salts and produce after calcination, high yields (>90%) of a quinternary, superconducting metal oxide. Moreover, the stability over time of the natural deep eutectic solvent and how this affects the overall outcome of the synthesis is discussed.