沉淀法制备掺锆氧化锌纳米粉末的形貌与光学性能

采用直接沉淀法制备未掺杂和掺杂Zr元素的ZnO纳米粉末,通过X射线衍射(XRD)分析、扫描电镜(SEM)、能谱分析(EDS)以及紫外可见光谱(UV-Vis)分析、光学性能测试等,研究Zr掺杂量(0~5%,摩尔分数)与溶液pH值(6.5~13.0)对粉末粒度、形貌与结构及光学性能的影响。结果表明:Zr掺杂使ZnO粉末粒径减小。Zr掺杂量为1%的粉末粒径最小,晶粒尺寸为28 nm,Zr完全进入ZnO晶格中;当Zr掺杂量增加到3%和5%时,粉末粒径增大,并出现ZrO2相。反应溶液的pH值为6.5时,Zr-ZnO纳米粉末形貌为类球形。随pH值增大,Zr-ZnO粉末形貌逐渐向短棒状转变,粉末粒径先减小然后增大。随Zr掺杂量从0增加到5%,ZnO的光吸收峰先出现"蓝移"后出现"红移",表明Zr掺杂可提高ZnO粉末的禁带宽度,随Zr含量增加,粉末的禁带宽度先增大后减小,1%Zr-ZnO的禁带宽度最大。

Morphology and optical property of zirconium-doped ZnO nanoparticles prepared by precipitation method

Undoped and zirconium-doped ZnO powders were successfully prepared by direct precipitation method. The effects of zirconium doping amount (0%?5%, atomic fraction) and pH (6.5?13.0) on powder size, morphology and structure, and optical properties of synthesized samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and UV–Vis spectroscopy. The results show that the grain size of zirconium-doped ZnO powder decreases. The smallest grain size about 28nm is obtained from 1% zirconium doped ZnO, and Zr entirely enters into the crystalline lattice of ZnO. When the zirconium doping amount reaches 3% and 5%, the grain size increases, and ZrO2 phase appeares. When pH value is 6.5, the morphology of Zr-ZnO powders is spherical-like. With increasing pH value, the morphology of Zr-ZnO powders gradually turns to short sticks. With increasing the amount of doped zirconium in ZnO (0?5%), the optical absorption spectra for synthesizing samples first shows blue shift, and then red shift, which indicates that doping of Zr can increase the band gap of ZnO powder. The band gap first increases and then dicreases, which reaches to the maximum from 1% zirconium doped ZnO.