普鲁士蓝类似物修饰多孔陶瓷球的制备及其As吸附能力

Preparation of Prussian Blue Analogue Modified Porous Ceramic Balls and Its Application in As Adsorption

通过粉末烧结和添加造孔剂法制备了直径为3～5 mm的多孔陶瓷球,烧结温度为1573 K,烧结时间1 h.利用碱处理法对该多孔陶瓷球进行了脱硅处理,降低了多孔陶瓷表面的Si/Al的物质的量之比,并且利用扫描电镜对碱处理前后多孔陶瓷球的表面形貌进行了表征.通过脱硅后陶瓷球与亚铁氰化钾溶液的反应,对多孔陶瓷球进行了表面修饰,在其表面生成了蓝色的普鲁士蓝类似物,并且利用X射线粉末衍射分析、X射线能谱分析和红外光谱分析对该蓝色物质进行了表征.利用砷酸二氢钠为砷源研究了修饰后陶瓷球的As离子吸附能力.

Porous ceramic ball with the size of 3～5 mm was prepared by powder sintering and space-holder method at 1573 K for 1 h. A desilication process was adopted to decrease the Si/Al molar ratio of porous ceramic ball surface. After being alkaline treated in 1 mol/L NaOH solution for 10 h, Si/Al molar ratio of porous ceramic ball surface was decreased from 4.5 to 1.76. Surface topography of the desilicated and undesilicated porous ceramic balls were investigated by scanning electron microscopy （SEM）. In the SEM images of desilicated porous ceramic ball, plenty of nanoparticles about 30 nm were observed. The reveal of the 30 nm nanoparticles means that the amorphous phase which was generated in the sintering process was greatly dissolved into the NaOH solution. A Prussian blue analogue was synthesized on the surface of the desilicated porous ceramic balls by the reaction between desilicated porous ceramic balls and potassium ferrocyanide solution. The Prussian blue analogue on the surface of desilicated porous ceramic ball was characterized by powder X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS） and infrared absorption spectrum （IR）, which showed that a kind of Al-Fe Prussian blue analogue was fabricated on the surface of the desilicated porous ceramic balls. The mechanism of the formation of Al-Fe Prussian blue analogue on the surface of desilicated porous ceramic ball was also investigated, which showed that the desilication process plays an important role in the formation of Al-Fe Prussian blue analogue. By the desilication process, the Si/Al molar ratio of porous ceramic ball surface was greatly decreased, which means more Al-activity sites were generated. With the mixture of desilicated porous ceramic balls and potassium ferrocyanide solution, the Fe（CN）64- was bonding to the Al atoms on the surface of desilicated porous ceramic ball and the Al-Fe Prussian blue analogue was generated. The As adsorption capacity of Prussian blue analogue modified porous ceramic ball was also investigated with NaH2AsO4 as arsenic source.