通过微乳液-水热法合成纳米级氢氧化钙，利用XRD、SEM、UV-Vis DRS、PL等对样品进行表征；考察其在可见光下对亚甲基蓝降解能力及其光催化性能。结果表明，当光强度为300 W时，5 min降解效率可达98.9%；氢氧化钙自身呈碱性的特性对亚甲基蓝降解有促进作用；光催化降解亚甲基蓝为间接染料光敏化作用，其中起主要作用的是羟基自由基，超氧自由基也有参与。氢氧化钙降解亚甲基蓝不仅有光催化作用，还发生均相离子反应使其降解为小分子物质。

Nanometer-scale calcium hydroxide is synthesized by means of microemulsion-hydrothermal method,and the samples are characterized by XRD,SEM,UV-vis DRS,PL and so on.The samples' photocatalytic performance is evaluated through degrading methylene blue under visible light.It is shown that the degradation efficiency can reach 98.9% in 5 minutes when the light intensity is 300 w.Calcium hydroxide itself shows alkaline characteristics,which can promote the degradation of methylene blue.Photocatalytic degradation of methylene blue is an indirect dye photosensitization,of which hydroxyl radicals play a major role,and superoxide radicals also participate in.When calcium hydroxide degrades methylene blue,unless photocatalytic reaction,homogeneous ion reaction also happens which degrade methylene blue into small molecules.

那平(1966-),男,博士,研究员,研究方向为高难废水及核废液后处理,naping@tju.edu.cn