## 3 Results and Discussion
### Photocatalytic Performance Results  
To evaluate the photocatalytic activity, the photodegradation of methyl orange dye was measured at concentrations of 10 and 20 ppm in aqueous solutions under UV light. The photocatalytic activity results for 10 and 20 ppm are shown in Figure 7, with \(C_{t}/C_{o}\) representing the ratio of the concentration at time \"t\" to the initial concentration of methyl orange over time in minutes. The highest photocatalytic efficiency during the first 60 min under UV light irradiation was observed for the TiO\({}_{2}\)/zeolite sample compared to pure TiO\({}_{2}\) in the anatase phase for both concentrations. The percentage of degradation efficiency was calculated according to Equation (3), and the results are shown in Table 4. For a concentration of 10 ppm, the TiO\({}_{2}\)/zeolite synthesized from ignimbrite residue as a source of zeolite degraded 94.71% of the dye in the first 60 min, while the synthesized TiO\({}_{2}\) degraded 83.93%, which was 10.78% lower. For the case of 20 ppm, the TiO\({}_{2}\)/zeolite photocatalyst (71.36%) also demonstrated higher efficiency than that of pure TiO\({}_{2}\) (56.78%). The pH remained constant at 3.5 for all cases. The photodegradation of MO with the various photocatalysts was fitted to the pseudo-first-order kinetic model [59]:  
\[\ln\left(\frac{C_{0}}{C_{t}}\right)=kt \tag{4}\]  
where \(C_{t}\), \(C_{0}\), and \(k\) represent the residual MO concentration, initial MO concentration, and pseudo-first-order rate constant, respectively. Figure 8 displays a graph representing the relationship between \(\ln(C_{0}/C_{t})\) and time for various concentrations of MO when util-zing TiO\({}_{2}\)/zeolite and pristine TiO\({}_{2}\) as photocatalysts. A robust fit for the first-order model was achieved, with a correlation coefficient (R\({}^{2}\)) exceeding 0.90 in all cases, as depicted in Table 5. Additionally, the rate constant was determined from these graphs, and the results are presented in Table 5. As shown in the figure and table, TiO\({}_{2}\)/zeolite exhibited the highest rate constants for the photodegradation of MO both for the concentration of 10 ppm (0.0436 min\({}^{-1}\)) and for that of 20 ppm (0.0207 min\({}^{-1}\)), and they were higher than those obtained for pure TiO\({}_{2}\) (0.0286 min\({}^{-1}\) and 0.0139 min\({}^{-1}\) for 10 and 20 ppm, respectively). The enhanced efficiency of the TiO\({}_{2}\)/zeolite photocatalytic material was attributed to the presence of zeolite, which facilitated the adsorption of the dye and the interaction with TiO\({}_{2}\) to break down these organic dyes, which agreed with other studies that were carried out [13; 15; 21]. The synergy of TiO\({}_{2}\) nanoparticles with zeolite boosts the photocatalytic activity by leveraging zeolites' high surface area and many active sites for enhanced adsorption of methyl orange [13]. This combination prevents nanoparticle aggregation and amplifies light adsorption. Furthermore, zeolites act as electron sinks, diminishing \begin{table}
\begin{tabular}{l c c} \hline \hline \multicolumn{1}{c}{**Sample**} & \multicolumn{1}{c}{**Concentration**} & \multicolumn{1}{c}{**\%Eff\({}_{deg}\)**} \\ \hline TiO\({}_{2}\)/zeolite & 10 & 94.71 \\ Pure synthesized TiO\({}_{2}\) & 10 & 83.93 \\ TiO\({}_{2}\)/zeolite & 20 & 71.36 \\ Pure synthesized TiO\({}_{2}\) & 20 & 56.78 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Comparison of the degradation efficiency for the samples. \begin{table}
\begin{tabular}{l c c c} \hline \hline \multicolumn{1}{c}{**Sample**} & \multicolumn{1}{c}{**Surface Area**} & \multicolumn{1}{c}{**Pore Volume**} & \multicolumn{1}{c}{**Average Pore**} \\  & **[m\({}^{2}\)/g]** & **[cm\({}^{3}\)/g]** & **Diameter** \\ \hline Zeolite analcime & 1.740 \(\pm\) 0.005 & 0.000489 & 2.1426 \\ TiO\({}_{2}\)—Sigma Aldrich & 80.571 \(\pm\) 0.278 & 0.022379 & 2.1420 \\ Synthesized TiO\({}_{2}\) & 86.951 \(\pm\) 0.346 & 0.025958 & 2.1505 \\ TiO\({}_{2}\)/zeolite & 169.079 \(\pm\) 0.802 & 0.042061 & 2.1411 \\ \hline \hline \end{tabular}
\end{table}