【摘要】 通过硫酸铝水解生成的氢氧化铝对金红石相纳米TiO2进行表面处理,利用X射线衍射、X射线光电子能谱、Zeta电位分析仪、透射电镜和比表面仪测试技术对纳米TiO2进行了表征,并测定了纳米TiO2光稳定性随包覆量的变化。结果表明,氢氧化铝所形成的包覆层是疏松和多孔的。当m(Al2O3)∶m(TiO2)=1∶10时,氢氧化铝以非晶态形式存在,当m(Al2O3)∶m(TiO2)≥1∶5时,出现了三羟铝石结构,三羟铝石的晶粒尺寸为20～25nm。从电子结合能的变化可以推测,包覆层的铝以化学键合的方式沉积在纳米TiO2的表面,形成了Al—O—Ti键。Zeta电位和比表面积的测试结果表明,随着m(Al2O3)∶m(TiO2)的增大,纳米TiO2颗粒的等电点由pH=4.2逐渐移至pH=8.0,比表面积缓慢下降。更多还原

【Abstract】 Nanosized TiO₂ in the rutile phase was coated with aluminum hydroxide obtained from the （hydrolysis） of aluminium sulfate as source material. The nanosized TiO₂ was characterize by means of XRD, XPS, Zeta potential, TEM and BET techniques. The photostability of nanosized TiO₂ was evaluated. The （results） reveal that the coating layer of aluminum hydroxide is loose and porous. Aluminum hydroxide is （amorphous） structure when m(Al₂O₃)∶m(TiO₂)=1∶10, while m(Al₂O₃)∶m(TiO₂)≥1∶5, bayerite structure appears and the crystal size of bayerite is 20²5 nm. According to the difference of electron binding energy, it can be inferred that Al atoms in the coating layer are attached to TiO₂ surface via Al—O—Ti bond. The Zeta potentials and BET surface areas show that along with the increase of m(Al₂O₃)∶m(TiO₂) the isoelectric point of nanosized TiO₂ shifts from pH=4.2 to pH=8.0 and BET surface area drops slowly.更多还原