空心椭圆状分级结构γ-AlOOH的无模板水热制备及吸附性能研究

Synthesis of Hollow Ellipsoid-Like Hierarchical γ-Al OOH via Template-Free Hydrothermal Method and Its Adsorption Properties

以硝酸铝为铝源、草酸钠为沉淀剂,采用无模板水热法制备了空心椭圆状分级结构γ-Al OOH。通过XRD、SEM、TEM和氮气吸附脱附法对样品进行了表征,探讨了分级结构γ-Al OOH的形成机理,并研究了其对刚果红的吸附性能。结果表明：草酸钠添加量影响勃姆石微观形貌及物相变化,当草酸钠添加量为2 mmol时,制备得到的空心椭圆状分级结构长度为1.7~2.2μm,宽度为0.8~1μm,组成单元为纳米窄片。该结构勃姆石的比表面积为147.45 m2/g,最可几孔径为3.5 nm,对刚果红的最大吸附量为99 mg/g。

Ellipsoid-like hierarchical γ-Al OOH materials were prepared by a template-free hydrothermal method by using aluminum nitrate（ Al（ NO3）3·9H2O） as aluminum source and Na2C2O3 as precipitating agent. The obtained samples were characterized by X-ray powder diffraction（ XRD）,scanning electron microscopy（ SEM）,transmission electron microscopy（ TEM） and N2 adsorption /desorption technique. The possible formation mechanism of the ellipsoid-like hierarchical γ-Al OOH was proposed based on the experimental results. In addition,the adsorption performance of hierarchical γ-Al OOH for Congo red was studied. The experiment results show that the micro-morphology of γ-Al OOH and phase change is controlled by the adding amount of Na2C2O3. When Na2C2O3was2 mmol,the ellipsoid-like hierarchical γ-Al OOH is obtained with an average length of 1. 7-2. 2um and width of 0. 8-1. 0um,which is assembled by thin nanosheet and exhibited a BET surface area of147. 45 m2/ g and a most probable pore size of 3. 5 nm. Meanwhile,the hierarchical γ-Al OOH shows a maximum adsorption capacity for Congo red（ CR） of 99 mg / g.