MOF-177/graphene composite as a selective sensor for nitro aromatic compounds
- PDF / 380,148 Bytes
- 7 Pages / 432 x 648 pts Page_size
- 41 Downloads / 193 Views
MOF-177/graphene composite as a selective sensor for nitro aromatic compounds Venkata Neti1,2 1 Department of Chemistry, University of Texas at El Paso, El Paso, Texas 79968 2 Current address: Department of Chemistry, University of Utah, Salt Lake City, UT 84112 E-mail: [email protected] ABSTRACT A zinc-based metal-organic framework, MOF-177, was synthesized on the surface of benzoic acid functionalized reduced graphene oxide (BFG). Large amount of BFG (30wt %) slightly improved the stability of the MOF on the graphene surface, decreased the porosity of the composite, and resulted in 1mm long and 50μm wide microrods of MOF-177/BFG composites which act as a selective sensor for trinitrophenol compared to trinitrotoluene. INTRODUCTION Graphene,1 and graphene based materials2,3 (graphene oxide (GO), chemically reduced graphene oxide (r-GO) and functionalized reduced graphene oxide) are versatile platforms for carbon-based materials. Reduced graphene oxides and functionalized reduced graphene oxides have attracted considerable attention, given their potential applications as sensors.4 Recently, Diels-Alder covalent chemistry of graphene was demonstrated on the basal plane of graphene for band gap engineering of single layer graphene devices.5 On the other hand metal-organic frameworks6-10 (MOFs), covalent organic frameworks (COFs),11-13 and porous organic polymers (POPs)14-18 have also attracted attention due to their potential applications for gas storage, catalysis, and lightharvesting.19 Recently, Li et al found that fluorescence of a 3D metal-organic framework, ([Zn2(oba)2(bpy)] DMA) was rapidly, reversibly and selectively quenched by nitro-aromatic explosives.20 Nitro aromatic explosives such as dinitrotoluene, trinitrotoluene and RDX pose severe security problems all around the world. The carboxylic acid and hydroxyl groups are mainly found at the edges of graphene oxide after oxidation of graphite, whereas epoxy groups are located in the middle of both sides of the graphene basal plane. Bandosz et al recently reported MOF–GO nanocomposites for efficient separation of gases.21 In these composites, linkages are made between epoxy groups on both sides of GO and [Zn4O]6+ secondary building units (SBU’s) from the MOF5.
1
Figure 1. Synthetic scheme for (a) MOF-177 (b) MOF-177/BFG composite and TEM image of the composite MOF-177/BFG.
In addition to this alternative MOF-5/GO composite material, Loh et al reported the synthesis of MOF-5 on the surface of benzoic acid functionalized reduced graphene oxide (BFG) to grow MOF-5 nanowires, which have interesting photoelectric transport properties.22 However, examples of MOF-graphene composites are still limited taking into account the structural versatility of MOFs. In an effort to develop carbon based sensors, we have been interested in investigating graphene based MOFs and their sensor properties. 1,3,5-triphenylbenzene is highly fluorescent and photochemically stable. A better degree of tunability and length of the structural motif can be accomplished by proper selectio
Data Loading...
