کلینوپتیلولیت

In the present study, the impact of immobilizing a BiOI-CuO heterojunction on clinoptilolite zeolite as a support for photocatalytic degradation of the organic pollutant methyl orange (MO) was investigated. To this aim, BiOI-CuO heterojunction photocatalysts with varying weight ratios of BiOI:CuO (2, 3, and 4) were synthesized and embedded in clinoptilolite matrix. Characterization techniques confirmed the successful synthesis of the photocatalysts. FESEM analysis revealed that immobilization of the heterojunction structure on the zeolite support reduced the number of agglomerations. This immobilization not only preserved the morphology of the semiconductors but also led to the formation of a more homogeneous and uniform structure. The results demonstrated enhanced photocatalytic performance for MO degradation due to the formation of a heterojunction between BiOI and CuO semiconductors and their immobilization on clinoptilolite. The combination of 20 wt.% BiOI and 10 wt.% CuO immobilized on clinoptilolite exhibited the highest removal efficiency for MO. This superior performance was attributed to the favorable dispersion and distribution of the active-phase semiconductors on the zeolite support, lower charge carrier recombination and an appropriate bandgap, as confirmed by characterization analyses. Under 2 h of UV light irradiation with a MO concentration of 20 ppm and a photocatalyst dosage of 0.5 g/L, a maximum MO removal efficiency of 85% was achieved under UV light irradiation.

Removal of bentazone herbicide through photodegradation process using nanostructured TiO2/Clinoptilolite composite was studied to investigate the potential of clinoptilolite natural support and the effect of the loaded TiO2 content on the process efficiency. For this purpose, TiO2/Clinoptilolite photocatalysts containing different amounts of titania (10, 20, 30, 40 wt.%) were synthesized using a simple and inexpensive wet impregnation method and characterized by XRD, FESEM, EDX, BET, PL, and UV-vis analyses. The characterization results confirmed the successful synthesis of nanocomposite samples and showed that the use of zeolitic support, reducing the recombination rate of electron-hole pairs, improves the dispersion of titania nanoparticles and reduces the accumulation of these particles. The performance results showed that by increasing the TiO2 loading up to 30 wt.%, the removal efficiency of bentazone increases, which is due to the greater number of available active sites. By further increasing the amount of TiO2 loading, the percentage of photocatalytic removal decreases because of the increment in the number of agglomerations on the catalyst surface and the decrement in the adsorption capacity. Also, the kinetic studies show a higher rate of bentazone degradation over the sample containing 30 wt.% of titania and the results follow the first-order kinetic reaction. In order to ensure the efficiency of the selected photocatalyst in the removal of other agricultural pesticides, its efficiency in the photocatalytic removal of paraquat herbicide was also evaluated, which showed good performance. Thus, it can be concluded that the immobilization of the optimal amount of titania on clinoptilolite, in addition to better and easier separation, leads to improved optical and structural properties, and ultimately increased photocatalytic performance.