Multifunctional Floating Titania-Coated Macro/Mesoporous Photocatalyst for Efficient Contaminant Removal

A multifunctional floating photocatalyst consisting of highly active well-ordered mesoporous TiO₂ (OMT) as a catalyst and polyurethane foam (PUF) as a floating substrate is synthesized successfully through a low-temperature ultrasonic and deposition approach. With the synthesized OMT/PUF composites, the multifunctionality of contaminant adsorption, dye degradation, and heavy metal removal can be achieved simultaneously. The prepared photocatalyst is characterized in detail by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, and N₂ adsorption. The results indicate that the OMT/PUF presents a hierarchical macro/mesoporous structure, which is favorable for the adsorption and diffusion of pollutants and for the efficient utilization of sunlight. The degradation of several model dyes including rhodamine B, methyl orange, methylene blue, and simultaneous reduction of hexavalent chromium are examined over the floating photocatalysts with sunlight irradiation under certain conditions. A synergistic effect between the degradation of dyes and the reduction of Cr^VI is observed for the dye-Cr^VI coexistence system. This novel floating OMT/PUF photocatalyst is very promising in the field of wastewater treatment.