微纳米氧化铜球粒晶的制备及其光催化性能

Preparation and photocatalytic activity of micro-nano copper oxide spherulite

以三水合硝酸铜和碳酸钠为原料,采用水热法在130、150、170℃下各分别反应8、16、24 h,合成了形貌各异的微纳米氧化铜球粒晶。使用X射线衍射仪和扫描电镜对产物的组成及形貌进行表征,初步分析了氧化铜球粒晶的形成与演化过程,并以亚甲基蓝为模拟污染物,对产物的光催化性能进行了研究。结果表明:氧化铜晶粒通过定向附着生长形成梭状或柱状纳米晶体,纳米晶体以自组装的方式逐步形成球粒晶;温度升高有利于增大氧化铜的成核速率,减小晶粒的尺寸,促使氧化铜纳米晶粒由梭形→板柱状→板状的晶形变化;延长恒温时间有利于形成表面形态完好的球粒晶;形貌不同的微纳米氧化铜球粒晶的最高光催化降解率均远大于市售氧化铜的最高光催化降解率,其中,130℃恒温16 h所得卷曲刺猬状氧化铜球粒晶的形貌、大小基本一致,光催化降解率高达96.56%。氧化铜的光催化降解率与球粒晶的比表面积、形态以及总孔体积有关。

In this paper,micro-nano-copper oxide spherulites with different morphology were prepared by hydrothermal method at 130,150 and 170℃for 8,16 and 24 h,with copper nitrate trihydrate and sodium carbonate as starting materials.The composition and morphology of the product were characterized by X-ray diffraction and SEM.Formation and evolution of copper oxide spherulites were analyzed.Photocatalytic properties of copper oxide spherulites were studied using methylene blue as a simulated pollutant.The results indicated that copper oxide grains formed spindle like or columnar nanocrystals by directional adhesion growth,the nanocrystals spherulites were formed by self-assembly.Increasing the temperature is beneficial to increase the nucleation rate of copper oxide and to decrease its grain size.Moreover,it can promote the change of crystal shape from shuttle crystal to plate column crystal to tabular crystal.Prolonging the reaction time is beneficial to form spherulites with perfect surface morphology.The highest photocatalytic degradation rate of micro-nano copper oxide spherulites is higher than that of general copper oxide powder.The morphology of curly hedgehog-like copper oxide spherulites was prepared at 130℃for 16 h.The photocatalytic degradation rate of the copper oxide spherulite reached 96.56%.The photocatalytic degradation rate of copper oxide is related to the specific surface area,morphology and total pore volume of spherulites.