SYNTHESIS OF A GRAPHENE/MOF COMPOSITE MATERIAL FOR IMPROVED HYDROGEN STORAGE PROPERTIES

摘要

Metal-organic frameworks (MOFs) and graphene have been receiving increasing attention in applications as sorbent materials for hydrogen storage [1, 2]. The attractiveness of MOFs in adsorption processes is derived from their high surface areas and the ability to possess tunable pore structure [3]. Despite the huge amount of publications and patents, there is still ongoing interest for either creating new MOFs or optimising their structural properties especially for their specific applications in hydrogen storage. On the other hand, graphene has over the last few years been identified as one of the promising materials for hydrogen storage due to the many interesting properties such as; improved mechanical strength, light in weight as well as high thermal and electrical conductivity [1,4]. Considering the above mentioned attractive properties that make graphene and MOFs ideal materials for gas storage applications, there is a need for careful and directed research effort on adapting graphene to derive enhanced hydrogen storage properties. Previous work in our laboratory had shown that it is possible to synthesise Zr-based MOF following a fast modulated synthesis strategy that enabled the production of micron-sized crystals using formic acid as a modulator [2]. As part of progression of this work, a key goal for our current work is to find ways of transferring graphene's intrinsic properties into MOF materials. In this case, a composite material consisting of Zr-MOF and reduced graphene oxide (rGO) was synthesized and analysed using various techniques such as SEM, XRD, BET and also tested for hydrogen uptake. Rather than follow the conventional method of physical mixing, our synthesis strategy involved the in situ method of incorporating rGO into the synthesis mixture of Zr-MOF.