## 4 Discussion
[7], who presented an increase in crystallite size with the calcination temperature and an accompanying broadening of the peaks at low calcination temperatures. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Studies** & **Synthesis Method** & **Nanomaterials** & **Particle Size** & **RBCs** & **Colemability** & **ROS Scavenging** & **Calcination** & **Greater Precursor/Gelatin** \\  & & & & & **Compatibility** & **Temperature** & **Ratio** \\ \hline  & & & Synthesis of Co\({}_{2}\) NPs & & & \\ \hline Present study & Sol-gel & Co\({}_{2}\) NPs & \textless{}10 nm & + & + & 550 \({}^{\circ}\)C & Larger NPs \\ \hline  & & & & & 400 \({}^{\circ}\)C & \\ [PERSON] 2019 [7] & Sol-gel & Co\({}_{2}\) NPs & 9–13 nm & & 500 \({}^{\circ}\)C & \\  & & & & & 600 \({}^{\circ}\)C &  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Studies** & **Synthesis Method** & **Nanomaterials** & **Particle Size** & **RBCs** & **ROS Scavenging** & **Calcination Temperature** & **Greater Precursor/Gelatin Ratio** \\ \hline Liu 2009 [75] & thermal decomposition & CaCO2 & \(\sim\)4 nm & + & + & 600 \({}^{\circ}\)C & \\  & NDPs & & & & & & \\ \hline Li 2019 [27] & hydrothermal & CaCO2 nanorods & \(9.6\pm 1.2\) nm & + & + & & \\  & CaCO2 nanocubes & \(57.2\pm 17.5\) nm & + & + & & \\  & CaCO2 nano-cctah & \(29.1\pm 11.7\) nm & + & + & & \\ \hline \multicolumn{6}{c}{Synthesis of NPs using gelatin} \\ \hline present & Sol-gel & CaCO2 NPs & \(<\)100 nm & + & + & 550 \({}^{\circ}\)C & Larger NPs \\ \hline [PERSON] 2011 [65] & UV irradiation & AgNPs NPs & 18.8 nm & & ambient & Larger yields \\ \hline \multicolumn{6}{c}{} \\ Azad 2018 [66] & Sol-gel & \multicolumn{2}{c}{\(\mathrm{L}\mathrm  
The sol-gel approach has gained popularity due to its flexibility, its ability to produce high-quality ultrafine nanostructures, its low operating temperature, and its ability to adjust particle size and shape. Many studies utilize the sol-gel method in order to create CeO\({}_{2}\) nanoparticles in a more environmentally friendly manner with similar findings to those found in the current work. In terms of particle size, [PERSON] compared NPs prepared by the sol-gel method and the coprecipitation method and concluded that with coprecipitation, the average size of CeO\({}_{2}\) nanoparticles was 4-37 nm in contrast to sol-gel using ethylene glycol as a solvent, which was 27.9-36.9 nm [69]. [PERSON] et al., synthesized via sol-gel elliptical/spherical CeO\({}_{2}\) nanoparticles with average sizes of \(\sim\)8 nm [70]. [PERSON] et al., studied the synthesis of different sizes of CeO\({}_{2}\) nanoparticles by utilizing varying amounts of a precursor using the sol-gel process and concluded that as the concentration of the precursor of cerium increases, the average nanoparticles size decreases, reaching average sizes of less than 100 nm [71]. This finding is in contrast to our study in which the largest Ce precursor amount presented NPs with a larger size (Figure 4). [PERSON] et al., synthesized via a sol-gel process a nano CeO\({}_{2}\) hydrosol which consisted of colloids with crystalline face-centered cubic nanostructured cerium dioxide. The particles of CeO\({}_{2}\) were approximately 10 nm in size [79]. [PERSON] et al. synthesized spherical nanoparticles with an approximate particle size of 9-13 nm [7]. All these studies and many more confirm that sol-gel is a reliable and trustworthy method for particle synthesis in the nanometer scale, as the NPs had a minimum particle size of 4.5 nm, as demonstrated by our TEM study (Figure 4). According to our results, in relation to the calcination temperature at 550 \({}^{\circ}\)C, XRD patterns and SEM/TEM analyses showed that the synthesized nanoparticles had 100% crystallinity (Figure 2) and presented homogeneity as shown in Figures 2-4. [PERSON] et al.