水热法合成柏拉图多面体CeO_2及其光催化性能分析

Hydrothermal synthesis of platonicpolyhedra CeO_2 and its photocatalytic activity

使用水热法,190℃下反应2,5,10,20h制备4组纳米CeO_2样品.对纳米CeO_2样品的微观结构、比表面积、能隙、光催化能力进行表征,分析合成样品的反应时间与光催化性能的关系.实验结果表明:CeO_2样品的微观结构为柏拉图多面体中的正八面体,且具有两端开口的圆柱形微孔,样品的能隙宽度随反应时间的变化而变化;CeO_2样品的最高光催化效率为20.65%;影响光催化能力的因素中,样品分散性的影响最大.

CeO2 nano-struetured samples were prepared by hydrothermaI method at 190 ℃ for 2, 5, 10, 20 h, respectively. Their phase structure, surface topography, mesoporous type, energy gap and the photocatalytic activity of the samples were characterized. The relation of photocatalytic activity and reaction time was studied in detail. This experiment showed that the crystal phase was octahedral shape in platonic polyhedra and the mesoporous type was the open cylinder. Energy gap varied with reaction time. The highest photocatalytic degradation rate of CeO2 was 20.65%. The influence of sample dispersion was the largest in the all factors which impacted the photocatalytic activity. The impact factor for photocatalytic activity of sample showed that the dispersibility might be more important than other factors in pohotocatalytic activity.