A comparative study of photocatalytic degradation of airborne styrene using TiO2 and ZnO nanoparticles immobilized on activated carbon

Background: With the growth of industries and advancing civilization, controlling air pollution from both human and natural sources has become a major concern. Styrene, a volatile organic compound (VOC), is recognized as a hazardous and toxic atmospheric contaminant. Methods: In this study, the removal of Styrene vapors using ZnO and TiO2 nanoparticles coated on activated carbon (AC) was investigated and the styrene removal capacity of AC-ZnO and AC-TiO2 catalysts was compared. The coated adsorbents were characterized using a field emission scanning electron microscope (FESEM), X-ray diffraction patterns (XRD), and the Brunauer-Emmett-Teller (BET) method. All laboratory-scale experiments were conducted at ambient temperatures. Styrene concentrations of 50, 100, and 300 ppm were tested at an input flow rate of 0.03, and 0.06 m3/h. Results: The AC-TiO2 catalyst had a styrene removal efficiency (RE) of 81%, as compared to 74% efficiency for the AC-ZnO catalyst, this is at a flow rate of 0.06 m3/h and a concentration of 50 ppm. The results indicated that increasing styrene concentrations reduced breakthrough time but increased adsorption capacity. Also, by increasing the inflow rate, the adsorption capacity decreased. At all concentrations and flow rates, the adsorption capacity of the AC-TiO2 catalyst was higher than the AC-ZnO catalyst. Conclusion: According to the results, it can be concluded that the AC-TiO2 catalyst is more effective in the removal of Styrene vapor from the air as compared to the AC-ZnO catalyst.