纳米尺度分散的TiO_2光催化降解甲醛的机理  

Study of the mechanism of HCHO photocatalysit degraded by nanosized TiO_2

作　　者：徐瑞芬[1] 胡学香[1] 胡伟康[1] 许秀艳[1] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029

出　　处：《化学研究与应用》2003年第5期715-717,共3页Chemical Research and Application

摘　　要：By analysing the energy level structure of nano-TiO2 and the performance of degrading formaldehyde,the photocatalytic mechanism of nano-TiO2 was discussed.It was found that the size of the particles is a key factor which determines the photocatalytic efficiency in the competing process between spearation and recombination of the charge-carriers.When particles dispersed at nanometer scale,the quantum size effect and the surface effciency of separation is strong,charge-carriers can quickly transfer to the surface.Them they react with the oxygen and water absorbed on the surface of materials.Thus two kinds of groups hydroxyl radicals and anion peroxide radicals,will form.Having good oxidize power,these groups can seize electron or hydrogen atoms from the polluted substances on the material surface.Subsequently,the chain reactions are induced.As a result,contaminations are mineralized and degraded.By analysing the energy level structure of nano-TiO2 and the performance of degrading formaldehyde,the photocatalytic mechanism of nano-TiO2 was discussed.It was found that the size of the particles is a key factor which determines the photocatalytic efficiency in the competing process between spearation and recombination of the charge-carriers.When particles dispersed at nanometer scale,the quantum size effect and the surface effciency of separation is strong,charge-carriers can quickly transfer to the surface.Them they react with the oxygen and water absorbed on the surface of materials.Thus two kinds of groups hydroxyl radicals and anion peroxide radicals,will form.Having good oxidize power,these groups can seize electron or hydrogen atoms from the polluted substances on the material surface.Subsequently,the chain reactions are induced.As a result,contaminations are mineralized and degraded.

关 键 词：纳米尺度 分散 TIO2 光催化降解 甲醛 机理 纳米二氧化钛 

分 类 号：O623.511[理学—有机化学] O643.36[理学—化学]