## 3 Results and Discussion
### Photocatalytic Evaluation  
Sol-gel (ZnO, TiO\({}_{2}\)) and powder (ZnO) films were created in our three earlier studies [33; 34; 35]. Both the silver ion modification method and the photo-fixation method are the same. For four hours, we broke down the medication (paracetamol) and organic dyes (Malachite green and methylene blue) in these three publications when exposed to UV and visible light. Using surfactants with two distinct molecular weights, we photo-fixed silver ions onto films from commercial TiO\({}_{2}\) powder in this paper. Due to the pollutants' shorter 3 h half-lives under UV and visible light, this approach is more successful. The contaminants were Malachite green and methylene blue. As visible light is known to cause photolysis in colored dyes, a control experiment was carried out to estimate the dye removal rates in the absence of a photocatalyst. The results are shown in Figure 5 for both MB and MG, indicating an upwards of 13.2% Malachite green lost due to photolysis within 4 h and a higher rate of 18% for Methylene blue, which is known to act as a photosensitizer and thus is more prone to photolysis. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Powder Films** & **Crystalline Size, nm** & \begin{tabular}{c} **Parameters of the** \\ **Crystalline Lattice, Å** \\ \end{tabular} & **Microstrains, a.u.** \\ \hline TP2 & 42.6 & \begin{tabular}{c} a, b: 3.7067 \\ \end{tabular} & \(0.9\times 10^{-4}\) \\ \cline{2-4}  & & \begin{tabular}{c} c: 9.5136 \\ \end{tabular} & & \(0.7\times 10^{-4}\) \\ \hline Ag, \(10^{-2}\)/TP2 & 39.5 & \begin{tabular}{c} a, b: 3.7055 \\ \end{tabular} & & \(0.8\times 10^{-4}\) \\ \hline TP4 & 38.5 & \begin{tabular}{c} a, b: 3.7058 \\ \end{tabular} & & \(0.8\times 10^{-4}\) \\ \cline{2-4}  & & \begin{tabular}{c} c: 9.6332 \\ \end{tabular} & & \\ \hline Ag, \(10^{-2}\)/TP4 & 36.3 & \
\begin{tabular}{c} a, b: 3.7136 \\ \end{tabular} & & \(0.6\times 10^{-4}\) \\ \cline{2-4}  & &
\begin{tabular}{c} c: 9.3809 \\ \end{tabular} & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Crystalline size and parameters of the crystalline lattice of pure and Ag\({}^{+}\) (\(10^{-2}\) M) modified TiO\({}_{2}\) films. Figure 4: XRD patterns of (**a**) Ag, \(10^{-2}\)/TP2 and (**b**) Ag, \(10^{-2}\)/TP4 powder films. Additionally, a dark phase adsorption experiment with both dyes was carried out for the pristine catalysts (TP2, TP4). The decrease in the concentration of dyes in both cases was \(\sim\)15% of the initial 10 ppm. The data from adsorption and photolysis are included in Figures 6 and 7. Figures 6 and 7 depict -Ln(C/C\({}_{\rm o}\)) plotted against irradiation time, revealing a constant reaction rate for the samples. It is noticeable that the increased surfactant molecular mass and silver concentrations enhanced the samples' photocatalytic behavior under both ultraviolet and visible light. Figure 5: Photolysis rates for MG and MB. Figure 6: Kinetics of removal of malachite green under UV (**a**,**b**) and visible (**c**,**d**) light. The results demonstrate that TP4 films have activity compared to TP2. The smaller crystallite size (38.5 nm), and greater surface area (14 m\({}^{2}\)/g) of TP4 facilitate, faster degradation of organic dyes. The TP4 films displayed better photocatalytic efficiency than the TP2 samples, attributed to the increasing molecular weight of the surfactant and the improved morphology, crystalline size, and grain growth of the samples. Increasing the surface area typically leads to greater substrate adsorption, enhancing electron and hole reaction with the substrates. However, a larger surface area can also accelerate the e\({}^{-}\)/h\({}^{+}\) recombination, reducing the reaction rate. Thus, the specific surface area influences photoactivity; a larger surface area photocatalyst is preferable when surface reaction dominates recombination, and vice versa.