温度对重铬酸铵热分解制备三氧化二铬的影响

Effect of temperature on preparation of chromium oxide by thermal decomposition of ammonium dichromate

以铬铁合金在氨水溶液中电化学氧化制得重铬酸铵,热分解后获得产品三氧化二铬。借助X射线衍射、扫描电子显微镜、紫外可见光分光光度计研究了热分解温度对三氧化二铬结晶度、形貌、粒径和色度的影响。研究结果表明:随热分解温度增加导致产物的结晶度提高,粒径增加;在850℃热分解,制备出铬质量分数大于99%、粒径为100nm、亮绿色的球形氧化铬绿。

Chromium oxide product was obtained by thermal decomposition with ammonium dichromate as raw material prepared by electro-oxidation of ferrochromium in ammonium solution.The effects of thermal decomposition temperature on crystallinity,morphology,particle size and color were studied by X ray diffraction,scanning electron microscope and ultraviolet visible spectrophotometer.The results showed that the crystallinity and particle size increased with the increase of thermal decomposition temperature.The spherical chromium oxide with the mass fraction of 99%and particle size of 100 nm was prepared by thermal decomposition at 850℃,which presented bright green.