# Structure Control Using Bioderived Solvents in Electrochemical Metal-Organic Framework Synthesis
## 3 Results
### Synthesis with GVL  
Using the synthesis conditions described in the previous literature for use with traditional solvents as a starting point [6], the quality of the crystalline MOF coatings obtained when using GVL as the solvent were optimized by varying linker concentration, solvent ratios, reaction temperature and reaction duration. The conditions detailed in Table 2 are the result of this optimization process. XRD patterns of the MOF coatings obtained when using GVL for Cu and BTC, Zn and mIM, Zn and bIM, Co and mIM, Zn and eIM and Zn and IM are shown in Figure 3.  
Similarly to the case when CyreneTM was used, replacing the traditional solvents with GVL results in no change to the phase being formed when reacting Cu with BTC (Figure 3A), Zn with mIM (Figure 3B) and Co with mIM (Figure 3D). The patterns are clearly of HKUST-1, ZIF-8 and ZIF-67, respectively [27; 28] however it is noticeable that the signal to noise ratio for HKUST-1 (Figure 3A) is much lower than previously and that the peaks for ZIF-67 (Figure 3D) are much narrower than those for ZIF-8 (Figure 3B).  
Figure 2: SEM images of the MOF coatings using CyreneTM as the solvent for: (**A**) Cu and BTC; (**B**) Zn and mIM; (**C**) Zn and bIM; (**D**) Co and mIM; (**E**) Zn and eIM; (**F**) Zn and IM.  
More interestingly, again just like when utilising CyreneTM, the use of GVL as a solvent has led to the formation of three entirely different MOF phases when reacting Zn with bIM (Figure 3C), Zn with eIM (Figure 3E) and Zn with IM (Figure 3F). In the case of Zn and bIM rather than forming the SOD phase ZIF-7, the RHO phase ZIF-11 has been obtained with high purity [31]. Reacting Zn and eIM in GVL has led to the formation of the RHO phase, previously observed as minority product when using traditional solvents, almost exclusively [32]. Finally, the use of GVL as a solvent has caused Zn and IM to form high purity ZIF-10, as opposed to any of the other phases observed when using either the traditional solvents or CyreneTM[33]. In each of these three cases using GVL as a solvent has led to the formation of a higher porosity, lower stability MOF phase than would otherwise have been obtained.  
The SEM images of these coatings (Figure 4) corroborate much of what was observed in the XRD data. The HKUST-1 coating (Figure 4A) is very thin, with areas of bare Cu  
Figure 3: XRD patterns of the MOF coatings obtained using GVL as the solvent for: (**A**) Cu and BTC; (**B**) Zn and mIM; (**C**) Zn and bIM; (**D**) Co and mIM; (**E**) Zn and eIM; (**F**) Zn and IM compared against predicted peak position values [27; 28; 31; 32; 33].  
metal clearly observable, which explains the low signal to noise ratio observed in the XRD (Figure 3A), and the observed crystal morphologies in Figure 4C, E and F are completely different to those observed when using the same reactants with CyreneTM as the solvent (Figure 2C,E,F). The use of GVL has also seemingly led to an improvement in the overall crystal quality, indeed all six products in this case exhibit clearly defined crystals with discernable morphologies.  
Figure 4: SEM images of the MOF coatings using GVL as the solvent for: (**A**) Cu and BTC; (**B**) Zn and mIM; (**C**) Zn and bIM; (**D**) Co and mIM; (**E**) Zn and eIM; (**F**) Zn and IM.