Sanaa Shenawi-Khalil, V. Uvarov, D. Charkin
2012
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Influential Citations
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Journal
Solid State Sciences
Abstract
Abstract We report here the first observation of a bismuth potassium nitrate Bi1.7K0.9O2(NO3)2, obtained via thermal decomposition of bismuth and potassium nitrate mixtures. The new compound is orthorhombic, space group Immm (71), Z = 2, with a = 3.8698(7) A, b = 3.8703(7) A, and c = 24.1271(4) A. Its crystal structure was refined from powder X-ray diffraction data by analogy with the mineral beyerite, Bi2O2Ca(CO3)2. The morphology and elemental composition of Bi1.7K0.9O2(NO3)2 were characterized using scanning electron microscopy (SEM) with energy dispersive X-Ray spectroscopy (EDS). Its phase transformations upon heating and products of its thermal decomposition were studied using XRD, TGA and FTIR. At 440 °C, Bi1.7K0.9O2(NO3)2 transforms to another basic bismuth potassium nitrate with demonstrates a very similar XRD pattern but slightly larger cell parameters. At 520 °C, the intermediate oxide nitrate decomposes into a mixture of crystalline α-Bi2O3 and KNO3. The as prepared Bi1.7K0.9O2(NO3)2 showed lower than TiO2 (Degussa P25) photocatalytic activity upon decomposition of a widely used model pollutant, Rhodamine B (RhB) and photooxidation of potassium iodide under UV–vis light irradiation. Interaction with potassium iodide in alkaline media resulted in formation of Bi5O7I.