Photocatalytic Activity of Dye Sensitized Hematite Nanoparticles on Cenospheres

Cenospheres were in this study firstly modified with KH550 silane coupling agent and polyurethane prepolymer, followed then by dyeing with C. I. Reactive Blue 14 dye. Nano-sized alpha-Fe2O3 particles were finally deposited on the cenospheres through an optimized hydrothermal method. The photoactive dye was employed as a sensitizer for enhancing the light harvesting efficiency of the alpha-Fe2O3 nanoparticles. The resultant cenospheres were characterized by various techniques, namely; field emission electron scanning microscopy, energy dispersive X-ray, X-ray diffraction, vibrating sample magnetometer, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and diffuse reflectance spectrum. The photoactivity of the dye-sensitized alpha-Fe2O3 particles on the cenospheres was analyzed by degradation of methylene blue under visible light. It was concluded that, in comparison with the alpha-Fe2O3 coated cenospheres, the dye-sensitized alpha-Fe2O3 coated cenospheres efficiently degraded the methylene blue under simulated visible light, exhibiting an enhanced photocatalytic activity. The preparation and photodegradation mechanisms are also discussed in detail in this paper.