## 3 Results and Discussion
### Impact of Washing Procedure  
According to the previous section, X-ray diffraction analysis was initially employed to investigate how different washing procedures (W1 and W2) affect the purity and crystallinity of the MF-S1 batch. The results are presented in Figure 4, which compares the XRD patterns of samples synthesized using protocol No. 1 S1 and subjected to varying washing procedures. Additionally, the spectrum of the MF-S1 batch (MOF material without any washing) is included as a reference point for comparison. The X-ray diffraction patterns of MF-S1-W1 and MF-S1-W2 indicate an enhancement in crystallinity compared to the unwashed MF-S1 batch. For example, the intensity of the primary diffraction peak at 20 \(\approx\) 4\({}^{\circ}\), characteristic of MIL-100(Fe), is more pronounced after washing. The improved crystallinity is clearly reflected in the well-defined crystallographic spectrum, which features sharper and more intense peaks, even at low angles of incidence. \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Sample**} & **BET Surface Area** & **Pore Volume** & **PSD** & **Density** \\  & **(m\({}^{2}\)/g)** & **(cm\({}^{3}\)/g)** & **(nm)** & **g/cm\({}^{3}\)** \\ \hline MF-S1 & 1199 & 0.369 & 1.678 & 2.4679 \\ MF-S2 & 1067 & 0.313 & 1.633 & 2.5335 \\ MF-S3 & 500 & 0.208 & 1.417 & 2.4679 \\ \hline \end{tabular}
\end{table} 
Table 2: Surface area and pore volume of MF-S1, MF-S2, and MF-S3 batches. The effect is more pronounced in MF-S1-W2 compared to MF-S1-W1, as the former displays sharper and more defined peaks, suggesting a higher level of crystallinity. This distinction indicates that MF-S1-W2 has undergone a more effective structural formation, resulting in a more well-ordered and refined structural formation compared to MF-S1-W1. This observation strongly indicates that the washing procedures applied may be effective in removing impurities and unreacted byproducts (such as ionic species and unreacted acid linkers), resulting in a purer and more crystalline structure in these particular samples. This enhanced structural purity is likely a key factor influencing the material's properties and its potential applications. With the aim to better evaluate the impact of the W2 washing protocol on the crystallinity of the MF-S1 batch, Figure 5 compares the XRD patterns of the MF-S2-W1 material, subjected to different washing durations (5 days, 10 days, and 15 days). The results demonstrate that a minimal immersion time of 5 days in distilled water does not induce significant alterations in the material's crystallinity. Conversely, a remarkable improvement in crystallinity is observed following a 10-day immersion period, resulting in a sample with an XRD pattern closely resembling that of the experimental  
Figure 4: XRD results of the sample synthesized by synthesis protocol No. 1 S1 before and after washing by protocols W1 and W2. Figure 5: XRD results of MIL-100(Fe) samples synthesized by synthesis protocol No. 1 and washed by washing protocol No. 1. MIL-100(Fe) framework. This finding suggests that extended immersion in distilled water facilitates the crystallization process within the MF-S1-W1 material, potentially leading to enhanced structural integrity and improved material properties. Figure 6a shows the FTIR spectra of samples prepared using protocol No. 1 (MF-S1 batch) and treated with various washing techniques. For comparison, the spectrum of an unwashed MF-S1 batch (MOF material) is also included. As previously mentioned, the spectrum of the unwashed MF-S1 sample showed a peak at 1037 cm\({}^{-1}\), which is not characteristic of MIL-100(Fe). This extraneous peak disappeared after the application of washing protocol No. 1. Additionally, the peak at 1710 cm\({}^{-1}\), associated with the stretching vibration of unreacted linker molecules, diminished. Similar observations were made for the MF-S1-W2 batch.