Journal of Catalysis, Vol.356, 75-84, 2017
Imidazole-derived graphene nanocatalysts for organophosphate destruction: Powder and thin film heterogeneous reactions
Promoting efficient organophoshate (OP) destruction has been of increasing interest, mainly due to their highly toxic nature and broad use as agrochemicals and chemical warfare. It is known that OP destruction can only be accomplished in the presence of catalysts, since they are knowingly stable. Hence, multifunctional materials have been targeted for this purpose since they can combine catalytic sites with features that enable easy handling, sensor projection for monitoring misuse and even large-scaled detoxification methods. Herein, we developed nanocatalysts derived from graphene oxide, which comprises reactive imidazole groups anchored by covalent functionalization. Two approaches were adopted: (i) a mild aqueous reaction leading to a powder, namely GOIMZ1; and (ii) a liquid/liquid interfacial functionalization, resulting in the thin film GOIMZ2. The nanocatalysts were applied in the destruction of OP and in the case of the toxic pesticide Paraoxon, impressive rate enhancements were obtained (10(8)-fold). Both catalysts were consecutively recycled, maintaining overall characteristics. We highlight the feasible handling of the nanocatalysts, that in the case of the powder, it can be easily filtered, washed and reused. For the thin film, the handling is even more practical, since it can be immersed in the contaminated media and separated easier than the powder. Overall, we show novel imidazole-derived nanocatalysts with promising catalytic efficiency towards OP destruction, which have potential for projecting sensors and detoxification processes, especially with the thin films. (C) 2017 Elsevier Inc. All rights reserved.