Advanced Materials and Nanotechnology

Biography

Biography: Abderrazzak Douhal

Abstract

Metal-Organic Frameworks (MOFs), a class of crystalline porous compounds, have emerged as smart materials with a wide range of uses and applications. Among them, luminescent MOFs have gained great attention owing to their applicability in optoelectronic devices, as fluorescent sensors or photocatalyst systems [1-3]. In this Lecture, I will talk about the results exploring the spectroscopic and photodynamical properties of a serie of Zr-based MOFs, and their possible uses in nanophotonics, photocatalysis and detection of explosive molecules[4-7]. Firstly, we investigated the photoproperties of Zr-NDC MOF, which is made of Zr-clusters and 2,6-naphthalene dicarboxylate linkers [4]. The absorption and emission properties of this MOF are mainly due to the naphthalene linkers, with a well-defined vibrational absorption and emission bands. Moreover, the interaction of neighboring linkers induces the formation of excimers, reflected in a red-shifted broad emission band. A detailed photodynamic study reveals a multiexponential behavior with three time constants assigned to excimers formation, monomers and excimers lifetimes. With this in mind, we have incorporated different dyes (Coumarin 153, Nile Red and DCM) into the MOF porous structure, in order to investigate the possibility of energy transfer processes from excited MOF to the trapped dyes [5]. Upon MOF excitation, we have observed and unraveled the mechanism of energy transfer to the trapped dyes. By controlling the amount of the dye incorporated into the MOF, we have synthesized two white light emitting materials, one containing a mixture of Coumarin 153 and Nile Red, and the other by adding DCM to the MOF. Both materials emit cool white light with CIE coordinates (0.32, 0.34 and 0.32, 0.31) very near to the ideal ones (0.33, 0.33)