纳米NiO的制备及其谱学特性研究

以醋酸镍、氢氧化钠为原料，吐温80为分散剂，通过固相反应制备了纳米级NiO。 用X射线衍射仪、透射电子显微镜、傅里叶红外光谱、紫外-可见分光光度等方法对材料的粒径、晶格畸变率、形貌以及红外、紫外-可见光的吸收性能进行了表征。结果表明：制得的纳米NiO产物为球形、属立方晶系，粒径大小在9～30 nm左右;晶格畸变率随粒径的增大而减小;纳米NiO红外吸收峰出现在437 cm-1处，与普通粒径的NiO光谱纯(484 cm-1)相比，其吸收峰红移了47 cm-1,体现了纳米NiO的表面效应;不同粒径大小的NiO对紫外-可见光的吸收特性不同。普通粒径的NiO光谱纯在紫外-可见光区域没有吸收，颗粒尺寸越小吸收波长越短，10 nm NiO的紫外-可见光吸收峰位于309 nm处，直接跃迁的光学能带隙约为4.2 eV，比体相材料(3.65 eV)增加0.55 eV，表现出明显的量子尺寸效应。对纳米NiO的谱学特性研究表明该材料在光电领域具有潜在的应用价值。

Study on the Preparation and Spectral Characteristics of Nano-NiO

The NiO nanoparticles with the size of 9-30 nm were prepared by solid state method using nickel acetate and sodium hydroxide as the raw materials,and Tween 80 as the dispersant.The structure,morphology,size,and infrared and UV-Vis spectra were characterized by XRD,TEM,FTIR and UV-Vis,respectively.The XRD and TEM revealed that the products are spherical with cubic structure.The infrared absorption band of the NiO nanoparticles(437 cm~(-1)) red-shifts 47 cm~(-1) compared with that of bulk NiO(484 cm~(-1)).The UV-Vis optical absorption is related with the size of the particles.The bulk NiO has no absorption in the UV-Vis region,while the 10 nm NiO nanoparticles have stronger absorption observed at the wavelength about 309 nm,and the direct band gap energy is estimated to be about 4.2 eV which is obviously blue-shifted 0.55 eV compared to that of bulk NiO(3.65 eV).The surface effect and quantum size effect of the NiO nanoparticles indicated that the products will have potential application in the optical and electrical areas.