Applied Catalysis B: Environmental 138–139 (2013) 128–140 Contents lists available at SciVerse ScienceDirect Applied Catalysis B: Environmental jo u r n al hom ep age: www.elsevier.com/locate/apcatb Solar light-activated photocatalytic degradation of gas phase diethylsulfide on WO 3 -modified TiO 2 nanotubes Mathieu Grandcolas a , Thomas Cottineau a , Alain Louvet b , Nicolas Keller a , Valérie Keller a,∗ a Institut de Chimie et Procédés pour l’Energie, l’Environnement et la Santé (ICPEES), CNRS, University of Strasbourg, 25 rue Becquerel 67087, Strasbourg, France b Direction Générale de L’Armement (DGA), DGA CBRN Defense, BP 3, 91710 Vert-le-Petit, France a r t i c l e i n f o Article history: Received 14 November 2012 Received in revised form 13 February 2013 Accepted 18 February 2013 Available online xxx Keywords: Photocatalysis TiO2 nanotubes Hydrothermal synthesis WO3 modification Diethylsulfide elimination a b s t r a c t Artificial solar light responsive high surface area WO 3 -modified TiO 2 nanotubes have been efficiently used for performing the gas phase photocatalytic degradation of diethylsulfide, taken as simulant for the live yperite Chemical Warfare blister Agent, known as mustard gas. They were prepared by impregnating hydrothermally-synthesized titanate nanotubes with tungstate salt prior to the final calcination step. The influence of the WO 3 content, the inlet diethylsulfide concentration and the relative humidity on the photocatalytic activity as a function of time on stream has been investigated in terms of DES removal efficiency and of deactivation behavior. Modification of TiO 2 nanotubes with 4 wt.% of WO 3 enhanced the photocatalytic activity in terms of DES removal efficiency and of resistance to sulfate deactivation. Correlation between the surface species and the on-stream activity and behavior of the photocatalysts was proposed, as well as possible reaction mechanism pathways. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Recent years have seen the emergence of numerous techniques which are of high interest for environmental applications, particu- larly for treating chemically- and biologically-contaminated water, air and substrates. Among them, photocatalysis offers significant opportunities in various areas [1], partly taking advantage from recent advances in the field of nanomaterials and in that of pho- tochemical engineering. Embedded into filtration systems, paints, coatings and other so-called functional materials, photocatalysis seems to establish itself as an innovative technique and to be part of technological advances gained in logic of sustainable development. The risk of hazardous chemical dispersion has become a grow- ing threat, increasing strongly the potential risks of exposure to toxic materials. It is thus necessary to consider materials and pro- tection systems for suitable decontamination. Dispersion of toxic agents results in both equipment and infrastructure contamina- tion, so that one should focus on ways that allow decontamination and reduce the risk of dispersion. Nowadays, most decontamina- tion systems are resources-, time- and logistics-consuming, and require large amounts of water, corrosives or toxics, so that they are not considered as environmentally friendly. There are currently decontamination systems that can degrade the targeted chemical ∗ Corresponding author. Tel.: +33 368852736; fax: +33 368852761. E-mail address: vkeller@unistra.fr (V. Keller). or biological agents. However, they must be implemented after the event and after first-responder intervention, so that, till the decontamination technology can operate, the risk remains with continuous hazards toward the contaminated people, the sur- rounding people and stakeholders. Photocatalysis has already been successfully used for degrad- ing organosulfur compounds such as diethylsulfide (DES), acting as a simulant for the live yperite Chemical Warfare Agent (CWA), blister agent also known as mustard gas [2–4], whereas it has also been scarcely directly applied on live blister yperite CWA [5–7]. One should also note the interesting investigations performed on the photocatalytic oxidation of nauseous organosulfides such as dimethylsulfides [8,9]. TiO 2 has been shown to be one of the best candidates for use as photocatalyst. Since the discovery of one-dimension nanocar- bons like nanotubes or nanofibers, and within the trend to develop similar carbon-free high aspect ratio nanomaterials, titania-based nanotubes have started to attract much attention for use in various applications [10], like photovoltaic cells, gas sensors, UV block- ers. They also targeted promising applications in photocatalysis or photo-electrocatalysis for environmental and renewable energy production technologies, and more generally for sustainable devel- opment applications, due to their unique behaviors resulting from their nanotubular structure [11–17]. The high aspect ratio struc- ture offers a large surface-to-volume ratio resulting in a large surface area available and enhanced adsorption capacity for the reactant adsorption step. It also allows possible size confinement 0926-3373/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.apcatb.2013.02.041