Zinc Oxide Nanoparticles-Immobilized Mesoporous Hollow Silica Spheres for Photodegradation of Sodium Dodecylbenzenesulfonate

ZnO-Immobilized mesoporous hollow silica spheres (ZnO/xMHSS; x=15, 30, 50 molar ratio of Zn/Si) were synthesized and examined as photocatalysts toward the degradation of sodium dodecylbenzenesulfonate (SDBS). The hollow structures of MHSS and ZnO-immobilized MHSS composite were evidenced by transmission electron microscopy analysis. X-ray diffraction results confirmed the presence of ZnO and a mesoporous structure in the synthesized materials. N-2 adsorption-desorption analysis also depicted the formation of a mesoporous structure and the increased surface area for the ZnO/xMHSS materials. Fourier transform infrared spectroscopy analysis revealed the formation of Si-O-Zn bonds due to interaction between ZnO and MHSS. The photocatalytic testing results indicated that all the ZnO/xMHSS materials showed improved efficiencies of 10-21% toward the photodegradation of SDBS when compared with bare ZnO. Among the prepared materials, ZnO/15MHSS was the best photocatalyst, which photodegraded 68% SDBS after 1h reaction. The kinetic study demonstrated that the photocatalytic reaction followed the second-order model.