## 3 Results and Discussions
### Ftir  
FTIR analysis was conducted to investigate the functional and chemical groups present in the synthesized ZS-ZnO-NPs. Figure 8 shows the FTIR spectra of the ZS-ZnO-NPs synthesized using different zinc salts. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Sample** & **Avg D\({}_{\text{XRD(nm)}}\)** & **D\({}_{\text{(101)}}\)** & **FWHM\({}_{\text{(101)}}\)** & **Crystallinity (\%)** \\ \hline a & ZnCl\({}_{2}\) & 9.3 \(\pm\) 0.5\({}^{\text{D}}\) & 11.94\({}^{\text{D}}\) & 0.70\({}^{\text{A}}\) & 94.6 \({}^{\text{A}}\) \\ \hline b & ZnSO\({}_{4}\cdot\)H\({}_{2}\)O & 10.9 \(\pm\) 0.7 \({}^{\text{C}}\) & 12.29 \({}^{\text{C}}\) & 0.68 \({}^{\text{B}}\) & 93.3 \({}^{\text{B}}\) \\ \hline c & Zn(CH\({}_{3}\)CO)\({}_{2}\cdot\)2H\({}_{2}\)O & 12.4 \(\pm\) 0.7 \({}^{\text{B}}\) & 13.06 \({}^{\text{B}}\) & 0.64 \({}^{\text{C}}\) & 92.5 \({}^{\text{C}}\) \\ \hline d & Zn(NO\({}_{3}\))\({}_{2}\cdot\)6H\({}_{2}\)O & 22.6 \(\pm\) 1.4 \({}^{\text{A}}\) & 25.33 \({}^{\text{A}}\) & 0.33 \({}^{\text{D}}\) & 83.5 \({}^{\text{D}}\) \\ \hline \hline \end{tabular} Note: “\(\pm\)” indicates the standard deviation, and uppercase letters (\({}^{\text{A}-\text{D}}\)) denote significant differences between samples based on statistical analysis.  
\end{table} 
Table 2: Results of diameter average from XRD (Avg D\({}_{\text{XRD}}\), nm), diameter at the most intense peak (D\({}_{\text{(101)}}\), nm), FWHM\({}_{\text{(101)}}\), and crystallinity degree (%) for ZS-ZnO-NPs synthesized using different zinc salts and a plant extract of _Phoneix dactylifera_ L. at pH 12: (a). ZnCl\({}_{2}\), (b). ZnSO\({}_{4}\cdot\)H\({}_{2}\)O, (c). Zn(CH\({}_{3}\)CO)\({}_{2}\cdot\)2H\({}_{2}\)O, and (d). Zn(NO\({}_{3}\))\({}_{2}\cdot\)6H\({}_{2}\)O. The observed peaks were assigned to various functional groups based on the literature [20; 65]. All of the synthesized ZS-ZnO-NPs exhibited characteristic peaks in the range of 4000-400 cm\({}^{-1}\), indicating the stretching vibrations of O-H, which can be attributed to the presence of adsorbed water on the particle surface [78]. The peak between 3500 and 3200 cm\({}^{-1}\) was attributed to the stretching vibration of hydroxyl (-OH) groups, while the peak at 1638 cm\({}^{-1}\) was assigned to the bending vibration of adsorbed water molecules [79]. The peaks observed at 2920 cm\({}^{-1}\) and around 2851 cm\({}^{-1}\) were attributed to the stretching vibrations of C-H [80]. The peaks at 1733, 1631, and 1438 cm\({}^{-1}\) were assigned to the bending vibration of the C=O, C=C, and -COO\({}^{-}\) group, respectively, while the peak at 1379 cm\({}^{-1}\) was attributed to the bending vibration of C-H bonds in ester group [80]. The peak observed around 1125 cm\({}^{-1}\) was assigned to the stretching vibration of the Zn-O bond [78]. The presence of this peak confirms the formation of ZS-ZnO-NPs. The intensity of this peak varied depending on the type of zinc salt used, indicating the influence of the precursor on the bonding characteristics of the nanoparticles. In addition, the peaks between 680 and 400 cm\({}^{-1}\) were attributed to the Zn-O bending vibration, which is also a characteristic peak of ZnO-NPs [20; 65]. The ZnCl\({}_{2}\) resulted in the highest absorbance among the synthesized ZS-ZnO-NPs, followed by ZnSO\({}_{4}\cdot\)H\({}_{2}\)O, Zn(CH\({}_{3}\)COO)\({}_{2}\cdot\)2H\({}_{2}\)O, and Zn(NO\({}_{3}\))\({}_{2}\cdot\)6H\({}_{2}\)O, as shown in Figure 8. The observed increase in absorbance could potentially be attributed to the smaller size of the nanoparticles. The observed trends indicate that there is a correlation between smaller particle sizes and a rise in absorbance and band area [78]. Finally, the FTIR spectra confirmed the presence of various functional groups on the surface of the synthesized ZS-ZnO-NPs, and the observed peaks were assigned to various functional groups based on the literature.