文献类型：期刊文献

英文题名：Photocatalytic degradation of low concentration formaldehyde and simultaneous elimination of ozone by-product using palladium modified TiO2 films under UV254+185nm irradiation

作者：Fu, Pingfeng[1,2];Zhang, Pengyi[1];Li, Jia[1]

第一作者：Fu, Pingfeng

通讯作者：Zhang, PY[1]

机构：[1]Tsinghua Univ, Sch Environm, State Key Joint Lab Environm Simulat & Pollut Con, Beijing 100084, Peoples R China;[2]Beijing Union Univ, Coll Arts & Sci, Dept Biol & Environm Sci, Beijing 100191, Peoples R China

第一机构：Tsinghua Univ, Sch Environm, State Key Joint Lab Environm Simulat & Pollut Con, Beijing 100084, Peoples R China

通讯机构：[1]corresponding author), Tsinghua Univ, Sch Environm, State Key Joint Lab Environm Simulat & Pollut Con, Beijing 100084, Peoples R China.

年份：2011

卷号：105

期号：1-2

起止页码：220-228

外文期刊名：APPLIED CATALYSIS B-ENVIRONMENTAL

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000291907400026)】；

基金：The authors gratefully acknowledge the financial supports from National Basic Research Program of China (2007CB613303), National Nature Science Foundation of China (50908132) and Tsinghua University Initiative Scientific Research Program.

语种：英文

外文关键词：Photocatalysis; Formaldehyde; Palladium modified TiO2; Ozone decomposition; Vacuum ultraviolet (VUV); Indoor air

摘要：Simultaneous elimination of formaldehyde and 03 by-product was investigated in the UV254+185nm photocatalysis with a continuous flow mode using palladium modified TiO2 films (Pd-TiO2). Formaldehyde (HCHO) was introduced at a low concentration (ca. 450 ppbv), typical of polluted indoor environments. Pd nanoparticles, deposited via an electrostatic self-assembly method, had uniform distribution on TiO2 films with an average size of 3-4 nm. Under UV254+185nm, irradiation, the steady state concentration of HCHO was reduced to 10-50 ppbv for a long irradiation period (>30 h), and catalyst deactivation was not observed. Modification of TiO2 with palladium could simultaneously increase the conversion of HCHO and O-3, especially at the high RH level, showing the excellent moisture-resistant behaviors. At the Pd loading of 0.3-0.4 mu g cm(-2), the O-3 conversion ratio increased over 3 times compared to pure TiO2. XPS analysis exhibited that PdO on the TiO2 was oxidized to mixture palladium oxides PdOx(x>1) under UV254+185nm irradiation. Due to high electron affinity of formed PdO2, the photogenerated electrons could be trapped by PdOx, thus improving the separation of e(-)/h(+) pairs. As the reduction of PdO2 and oxidation of PdO coexisted, the PdOx could be dynamically stabilized, thus increasing the photoactivity of Pd-hO(2). Under UV254+185nm irradiation, the ozone might be decomposed on the Pd-TiO2 via two different routes, i.e., photocatalytic reduction of O-3 on exposed TiO2 and decomposition of O-3 on PdOx particles involved with UV irradiation and trapped electrons. (C) 2011 Elsevier B.V. All rights reserved.