利用具有keggin结构硅钨酸还原Cr（Ⅵ）制备CrPO_4纳米粉体

摘要

A convenient photochemical technique was developed for the synthesis of CrPO4 product by reducing Cr2O72-with Keggin silicotungstic acid.The synthesis process was monitored by UV-vis spectra.The studies of Fourier transform infrared（FT-IR）,Powder X-ray diffraction（XRD）,scanning electron microscopy（SEM）,and transmission electron microscopy（TEM） show that the obtained product was spherical CrPO4 nano-powder with the diameter of about 500 nm.The probable synthesis mechanism associated with the photochemical reducing property and template action of Keggin silicotungstic.%以具有Keggin结构硅钨酸为光催化还原剂,用光致还原Cr2O72-的方法制备了磷酸铬纳米粉体,Cr2O72-的还原过程用紫外-可见光谱进行监测。通过红外光谱（FT-IR）、X射线衍射（XRD）、扫描电镜（SEM）和透射电镜（TEM）分析表明所制产物为无定形磷酸铬,具有较规则的球形结构,平均粒径约为500nm。其合成机理是：在紫外光的照射下,当存在有机化合物时,形成了还原态的硅钨酸,还原态的硅钨酸将Cr（VI）还原为Cr（Ⅲ）,与体系中的PO43-结合生成磷酸铬,由于硅钨酸与磷酸铬之间存在结合力,硅钨酸对磷酸铬纳米颗粒的形成又起到了模板的作用。