颜料二氧化钛光催化特性评价

摘要

The photocatalytic activity evaluation of submicron-sized pigmentary titania using the degradation of Rhodamine B under ultraviolet radiation in a slurry reactor was studied.The effects of titania concentration,Rhodamine B concentration,and wavelength and power of the light source on reaction rate were investigated.The optimal operation conditions for evaluating the photocatalytic activity of pigmentary titania particles were determined.The experimental results showed that the photocatalytic degradation of Rhodamine B by pigmentary titania was an apparent first order reaction.The photocatalytic reaction rate was high under the conditions of a titania concentration of 4 g · L-1,Rhodamine B concentration in the range of 2-10 mg · L-1,and the use of the main emission peak of the light source at 254 nm,which were suitable for evaluating the photocatalytic activity of pigmentary titania.The photocatalytic activity of titania particles with a dense silica coat was measured under these optimized reaction conditions,which showed that this method could be used to evaluate the photocatalytic activity of the pigmentary or film coated titania quantitatively and rapidly.%采用悬浆外照式光催化反应器,研究了在紫外光照下低活性颜料二氧化钛光催化降解罗丹明B的反应动力学特性.考察了二氧化钛浓度、罗丹明B浓度、紫外线波长及光强对光催化反应速率的影响,确定了适合颜料二氧化钛光催化特性评价的优化检测条件.研究表明,颜料二氧化钛光催化降解罗丹明B具有一级反应动力学特性.确定颜料二氧化钛光催化特性检测方法的优化操作条件为二氧化钛浓度约为4 g·L-1、罗丹明B浓度为2～10 mg·L-1、紫外光源主发射波长为254 nm.实验检测了表面包硅二氧化钛样品的光催化特性,表明该检测方法能够对颜料二氧化钛及包膜二氧化钛的光催化特性进行快速定量的评价.