## 3 Results and Discussion  
The X-ray diffraction patterns of the reference ZnO sample after treatment at 170 \({}^{\circ}\)C showed narrow and sharp diffraction peaks, corresponding to a well-crystallized wurtzite polycrystalline phase (Figure 2: inset). The plant extract influenced the phase composition of the biosynthesized samples: the powders consisted of wurtzite phase and a small quantity of hydroxide zinc carbonate (Figure 2). The increased concentration of the MA extract resulted in a broadening of the peaks, i.e., it suppressed the crystallization degree (the (101) peak intensity decreased significantly). The hydroxide zinc carbonate phase became almost amorphous. Similar results were obtained by [PERSON] et al. for plant-mediated ZnO, using _V. trifolia_ extract [40]. The mean crystallite size (D), lattice strain (\(\varepsilon\)), and unit cell parameter (a) of the zinc oxide and hydrozinctic phases are represented in Table 1.  
These parameters were calculated by the PowderCell 2.4 program [41] and using the Williamson-Hall equation [42], and they are listed in Table 1. The average crystallite size of the wurtzite and hydrozinctic phases decreased with increasing amount of the MA plant extract used for the preparation of samples. The mean crystallite size of the ZnO and hydrozinctic phases in G2 was smaller than that in sample G1 and reference ZnO ([PERSON] et al. ), proving that the crystallite sizes of the green synthesized ZnO decreased with increasing amount of the plant extract [43]. The higher concentration of the plant extract led to effective stabilizing and capping of the ZnO nanoparticles, thus preventing particle aggregation and the particle growth rate. Hydroxide Carbonate (Hydrozincite) Zn5(OH)6(CO3)2, PDF 72-1100, Wurtzite-PDF 89-7102. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sample** & **Phase** & **D, nm** & \(\varepsilon\times\)**10\({}^{-3}\), a.u.** & **a, Å** \\ \hline G0 & Wurtzite & 14.8 & 1.1 & 3.249 \\ \hline \multirow{3}{*}{G1} & Wurtzite & 9.8 & 4.2 & 3.257 \\ \cline{2-5}  & Hydrozinctic & 11.5 & 3.6 & 13.714 \\ \hline \multirow{3}{*}{G2} & Wurtzite & 8.6 (left) & 3.3 & 3.245 \\ \cline{2-5}  & Hydrozinctic & 7.6 & 4.2 & 13.720 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Calculated values of the mean crystallite size (D), lattice strain (\(\varepsilon\)), and unit cell parameter (a) of the wurtzite and hydrozinctic crystallographic phases. Figure 2: XRD patterns of bio-mediated samples and the reference sample G0 (inset); **o**-Zinc Hydroxide Carbonate (Hydrozincite) Zn5(OH)6(CO3)2, PDF 72-1100, Wurtzite-PDF 89-7102. Figure 3a represents the chrysanthemum-like morphology of the G0 sample, while Figure 3b reveals a plate-like structure in aggregated form--conglomerates of the bio-mediated particles. Figure 4a represent the TEM of the reference sample, which consists of many aggregated particles with different sizes. When the **MA** extract was added as a reducing agent, the samples were mainly composed of tiny separated particles, which confirms the role of **MA** extract for prevention or retardation of particle agglomeration (Figure 4b). The particle size of the plant-mediated powder G1 in the TEM photograph was about 30 to 100 nm, which is higher than that obtained by [PERSON]'s equation. EDX analyses of all samples were carried out at six different points and revealed a similar elemental composition. Zinc, oxygen, and carbon only without any other elements were registered in the spectrum of the reference samples (Figure 5). Figure 4: TEM photographs of G0 (**a**) and G1 (**b**) powders. Figure 3: SEM photographs of G0 (**a**) and G1 (**b**) powders. All of the samples had similar pore size distribution curves. The reference ZnO powders exhibited one narrow peak corresponding to micropores (size up to 10 nm) and a broad area peak, corresponding to a small quantity of mesopores within the region of 20 to 50 nm (Figure 6).