Hydrothermal synthesis of Pb2SnO4

Fine, yellowish powder of Pb2SnO4 with elongated crystalline morphology was synthesized hydrothermally in an alkaline system. To prepare a pure produc t, the mineralizer NaOH should be at a suitable concentration. In compariso n with the solid-slate method, the hydrothermal synthesis of Pb2SnO4 requir es much milder reaction conditions. For some metastable phases such as PbO, 3PbO-H2O and PbSnO3-2H(2)O transformed into Pb2SnO4 with increase in hydro thermal reaction temperature and reaction time. Pb2SnO4 is considered to be the thermodynamically stable phase in the alkaline hydrothermal system of PbO and SnO2. Reaction temperature and reaction time influenced the size an d aspect ratio of the elongated particles. In this work, no PbSnO3 phase wa s found under any hydrothermal conditions, even though the molar ratio of t he starting material was 1:1. (C) 1999 Elsevier Science Ltd.