# Structure Control Using Bioderived Solvents in Electrochemical Metal-Organic Framework Synthesis
###### Abstract  
Electrochemical synthesis of metal-organic frameworks (MOFs) has proven to possess many environmental advantages over traditional synthesis methods such as reduced energy use and shorter reaction times. However, the use of toxic, fossil fuel derived solvents such as \(N\),\(N\)-dimethylformamide (DMF) presents a challenge to the environmental credentials of this method that has yet to be dealt with. Here, we investigate bioderived solvents, Cyrene(tm) and \(\gamma\)-valerolactone (GVL), as an alternative for the synthesis of a range of MOFs via the anodic deposition method. The obtained MOF materials are characterized using \(\chi\)-ray diffraction (XRD) and scanning electron microscopy (SEM) to confirm their identities and morphologies and for comparison with MOFs synthesized using the traditional DMF-based solvent systems. When using Cyrene(tm) and GVL solvents, crystalline MOF materials were obtained of comparable quality to those afforded using DMF. However, in several cases, using Cyrene(tm) or GVL led to the formation of less stable, higher porosity MOF structures than those obtained using DMF, indicating that the larger bio solvent molecules may also play a templating role during the synthesis. This study successfully demonstrates the first-time electrochemical synthesis of MOFs has been performed using bio solvents and has highlighted that the use of bio solvents can provide a route to obtaining lower density, higher porosity MOF phases than those obtained using traditional solvents. electrochemical synthesis; metal-organic frameworks; bioderived solvents +
Footnote †: journal: Applied Sciences  
1 Aston Institute of Materials Research, Aston University, Birmingham B4 7 ET, UK 1  
Footnote 1: email: {hindi,m.Massengo,l.,j.Hammerton,j.D.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.J.,m.,m.J.,  
One type of material which requires the use of unsustainable solvents as part of its synthesis are metal-organic frameworks (MOFs) and particularly a subset known as zeolitic-imidazolate frameworks (ZIFs) [5]. MOFs are a pioneering type of highly ordered crystalline and porous material that have attracted much attention within scientific research in recent years. They consist of metal ions, or metal ion clusters, and heteroatom-containing organic molecules linked together via multiple coordination bonds to form complex architectures [6]. The discovery of their immensely practical properties such as a large distinct surface area [7], variable morphologies [8] and tunable structures [7] has opened an abundance of potential applications, many of which are perhaps yet to be discovered. Current functions of MOFs that are also under study include natural gas storage [9], drug delivery [10] and chromatography [11]. The traditional method of MOF production is solvothermal synthesis [12]. Solvothermal synthesis of MOFs utilizes solvents like \(N\),\(N\)-dimethylformamide (DMF), extremely high temperatures and high pressures [13]; all extremely unattractive from a green chemistry perspective. New methods for MOF synthesis that address some of these problems have been developed such as microwave-assisted synthesis [14] and mechanochemical synthesis [15], but problems remain with regard to the low yields that such methods achieve [15]. Electrochemical MOF synthesis is another novel synthetic route for MOFs that does not suffer from the same issues around low yield, which can proceed via either a cathodic or anodic mechanism [16; 17]. The anodic method is particularly interesting from a green chemistry perspective as only the organic linker reactant is dissolved into the solvent, compared to a more complex cocktail of chemicals required for the cathodic method [17]. Electrochemical MOF synthesis offers significant green chemistry related advantages compared to alternative synthesis routes. The process is continuous and requires shorter reaction times lower temperatures and reduced pressures, meaning less energy input is needed.