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, P.

机构：[1] State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; [2] Department of Biological and Environmental Sciences, College of Arts and Sciences, Beijing Union University, Beijing 100191, China

第一机构：State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China

通讯机构：[1]State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, 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：EI(收录号：20112214017751)

语种：英文

外文关键词：Ozone - Titanium dioxide - Photocatalysis - Palladium compounds - Irradiation - Catalyst deactivation - Electrons - Self assembly - Electron affinity

摘要：Simultaneous elimination of formaldehyde and O3 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. 450ppbv), 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 3-4nm. Under UV254+185nm irradiation, the steady state concentration of HCHO was reduced to 10-50ppbv for a long irradiation period (>30h), and catalyst deactivation was not observed. Modification of TiO2 with palladium could simultaneously increase the conversion of HCHO and O3, especially at the high RH level, showing the excellent moisture-resistant behaviors. At the Pd loading of 0.3-0.4μgcm-2, the O3 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-TiO2. Under UV254+185nm irradiation, the ozone might be decomposed on the Pd-TiO2 via two different routes, i.e., photocatalytic reduction of O3 on exposed TiO2 and decomposition of O3 on PdOx particles involved with UV irradiation and trapped electrons. ? 2011 Elsevier B.V.