尖晶石型CoCr_2O_4纳米粉体的制备及表征

Preparation and Characterization of Spinel-type CoCr_2O_4 Nano-particle

通过溶胶-凝胶法制备了不同焙烧温度和不同焙烧时间的CoCr2O4纳米粉体,用热重-差热分析仪（DTA-TG）、X射线衍射光谱仪（XRD）和紫外-可见分光光度计（UV-Vis）对其成晶温度、晶体结构和光响应性能进行了表征。结果表明,所制备的CoCr2O4纳米粉体均是尖晶石结构,属立方晶系,Fd-3m（227）空间群,纳米粒径尺寸在10-50 nm,在550-700 nm范围内有较强的可见光吸收。随着焙烧温度的升高,晶粒尺寸增大,CoCr2O4在600℃时禁带宽度最小,其Eg为1.61 eV。随着焙烧时间的延长,晶粒尺寸增大,CoCr2O4在2 h时的禁带宽度最小,其Eg为1.59 eV。

Spinel nanoparticle of CoCr2O4 was prepared by the salt sol-gel method,and the prepared sample was characterized by DTA-TG,XRD and UV-Vis.The result showed that the prepared nano-particle CoCr2O4 which was spinel structure belonged to cubic,Fd-3m（227） space group.Nano-size range was 10-50 nm.There was a stronger visible light absorption at the 550-700 nm.With increasing of roasting temperature,the size of CoCr2O4 increased.At 600 ℃,the band gap of CoCr2O4 was minimum and the Eg was 1.61 eV.With increasing of the roasting time,the size of CoCr2O4 increased.At 2 h,the band gap of CoCr2O4 was minimum and the Eg was 1.59 eV.