纳米Au/TiO_2薄膜真空紫外光催化降解甲醛

Vacuum ultraviolet photocatalytic degradation of formaldehyde and ozone decomposition by Au/TiO_2 nanocomposite film

为提高真空紫外光催化对甲醛的去除率并降低副产物O3的浓度,采用低温吸附法在TiO2薄膜上负载纳米Au.研究比较了UV254nm光催化(TiO2/UV)、真空紫外光降解(VUV)、真空紫外光催化(TiO2/VUV)等3种方法对低浓度甲醛的降解效果.结果表明,TiO2/VUV对甲醛的去除率显著高于VUV和TiO2/UV.TiO2表面负载纳米Au粒子能促进光生电子和空穴的分离.因此,在真空紫外光催化降解过程中,Au/TiO2不仅提高甲醛的降解率,还显著分解副产物臭氧,使尾气臭氧浓度降低32%.而且Au/TiO2薄膜在真空紫外光催化过程中具有很好的稳定性.

To increase VUV （vacuum ultraviolet） photocatalytic efficiency for removing formaldehyde and decomposing its byproduct,i.e.ozone （O3）,Au nanoparticles was supported on TiO2 nanocomposite film with low-temperature adsorption method.Three methods,i.e.UV254nm photocatalysis （TiO2/UV）,VUV photolysis （VUV） and VUV photocatalysis （TiO2/VUV） were compared to degrade low concentration formaldehyde in the gas phase.The results showed that the removal ratio of formaldehyde in the TiO2/VUV process was much higher than that in the TiO2/UV or VUV photolysis process.Deposition of Au nanoparticles on TiO2 significantly improved the separation of photogenerated electrons and holes.Accordingly,in the VUV photocatalysis,Au/TiO2 not only increased the removal ratio of formaldehyde,but also significantly decomposed ozone.The concentration of residual O3 was decreased 32%.Moreover,Au/TiO2 film was stable in the VUV photocatalysis process.