The synthesis of new bismuth basic nitrate complex oxides by the soft processing (II) - α - Bi2O3-HNO3-H2O system

The formation diagram of α-Bi2O3-HNO3-H2O system was studied using hydrothermal or wet method. Three kinds of compound of bismuth basic nitrate complex oxides were separated as single phases and determined their chemical compositions. The existence of these phases was previously found by XRD measurements, although those phases have been obtained only as mixture of multi phases precipitates. The new compounds have the chemical composition of Bi2(NO3)O2(OH)&middot7H2O, Bi2(NO3)O2(OH)&middotH2O, and Bi4(NO3)O2(OH)7, respectively. At the same reaction conditions of temperature (above 60°C) and pH in the α-Bi2O3-HNO3H2O system and the BiONO3-KOH-H2O systems, it was affirmed that the same kind of precipitates were formed regardless of the kind of starting reagents.