title: Dual-Enhanced Photocatalytic Activity of Fe-Deposited Titanate Nanotubes Used for Simultaneous Removal of As(III) and As(V).
abstract: Fe-deposited titanate nanotubes (Fe-TNTs) with high photocatalytic activity and adsorptive performance were synthesized through a one-step hydrothermal method. Initial As(III) oxidation followed by As(V) adsorption by Fe-TNTs could simultaneously remove these two toxic pollutants from aqueous solutions. The apparent rate constant value for photo-oxidation of As(III) under UV irradiation by Fe-TNTs was almost 250 times that of unmoidified TNTs. Under visible light, the Fe-TNTs also exhibited enhanced photocatalytic activity after Fe was deposited. Fe3+ located in the interlayers of TNTs acted as temporary electron- or hole-trapping sites, and attached α-Fe2O3 played the role of a charge carrier for electrons transferred from TNTs. These two effects inhibited electron-hole pair recombination thus promoting photocatalysis. Moreover, the As(V) adsorptive performance of Fe-TNTs also improved, owing to the presence of additional adsorption sites, α-Fe2O3, as well as increased pHPZC. Furthermore, Fe-TNTs exhibited good photocatalytic and adsorptive performace even after 5 reuse cycles. The present tests, concerning an initial As(III) photocatalysis and subsequent As(V) adsorption process, highlight the feasibility and importance of Fe used to modify TNTs. This study proposes a feasible method to simultaneously remove As(III) and As(V) from contaminated water using a novel Ti-based nanomaterial.
authors: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University , Beijing 100871, China.|Environmental Engineering Program, Department of Civil Engineering, Auburn University , Auburn, Alabama 36849, United States.
authors: Wen
authors: W
authors: Liu
authors: Environmental Engineering Program, Department of Civil Engineering, Auburn University , Auburn, Alabama 36849, United States.
authors: Xiao
authors: X
authors: Zhao
authors: Institute of Energy Systems, School of Engineering, The University of Edinburgh , The King's Buildings, Edinburgh EH9 3JL, United Kingdom.
authors: Alistair G L
authors: AG
authors: Borthwick
authors: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University , Beijing 100871, China.
authors: Yanqi
authors: Y
authors: Wang
authors: The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University , Beijing 100871, China.
authors: Jinren
authors: J
authors: Ni
keywords: As; Fe-deposited; dual-enhanced; photocatalytic activity; titanate nanotubes; visible light