Co_3O_4/Fe_2O_3核-壳粒子的制备及光学性能研究

Preparation of Co_3O_4/Fe_2O_3 Core-Shell Particles and Their Optic Properties

在单分散准球形-αFe2O3纳米颗粒的悬浮液中,在氨碱催化下,CoCl2水解产生的Co(OH)2沉积在-αFe2O3纳米颗粒表面,形成核-壳粒子.经500℃热处理后,壳层物质晶化为立方晶系Co3O4,壳层厚度约为6 nm.不同的氨碱液对核-壳结构产生影响,在1 mol.L-1尿素溶液的催化下,得到均匀的核-壳结构.应用TEM和XRD分析了产物结构,并利用UV-Vis光谱对复合材料的光吸收特性进行了研究.与-αFe2O3纳米颗粒的吸收光谱比较,在光激发下,Co3O4/Fe2O3核-壳粒子光吸收特性发生改变,在可见光区产生新的强吸收峰.

The amorphous Co（OH）2 obtained from the hydrolysis of CoCl2 under the catalysis of ammoniac base could be deposited on the surface of monodispersed pseudo-spherical α-Fe2O3 nanoparticles to form core-shell particles. After the heat treatment at 500 ℃, the structure of shell layer crystallized into cubic Co3O4 with a thickness about 6 nm. Different ammoniac bases and their concentrations would affect the structure of the core-shell particles, and it became homogeneous if catalyzed in 1 mol· L^-1 urea solution. TEM and XRD were used to analyze the structure of the core-shell particles. Compared to pure a-Fe2O3 nanoparticles, the UV-Vis spectrum of the core-shell particles showed that their optic properties were changed under photoexeitation and a new absorption peak with maximum absorbanee appeared in visible region.