Novel Floating TiO₂ Photocatalysts for Polluted Water Decontamination Based on Polyurethane Composite Foam

Abstract

This paper describes the fabrication of new floating photocatalysts based on composites of low-density polyurethane foams through simple in situ polymerization. Different amounts of TiO₂ were immobilized on polyurethane foams after pre-immobilization of TiO₂ onto organic montmorillonite. The coexistence of TiO₂ and montmorillonite on the polyurethane foams was confirmed by X-ray diffraction, scanning electron microscopy, and Fourier Transform Infrared Analysis. Photocatalytic efficiencies were evaluated from the degradation of Bisphenol A. More than 83% of the initial Bisphenol A was degraded in 2 h which was better than the reference photocatalysis by photocatalyst prepared by direct embedding. The degradation kinetics of Bisphenol A follow the apparent-first-order kinetics with the apparent degradation rate constant (k_ap) increases dramatically from 0.0063 min⁻¹ to 0.0141 min⁻¹ as TiO₂ loading increases from 10wt% to 40wt%. The density of all the prepared catalysts varied from 0.31 g cm⁻³ to 0.62 g cm⁻³, indicating the photocatalysts possess excellent floating properties which help directly utilize radiation in photocatalysis without any energy loss incurred in transmitting through water. To conclude, the results demonstrate that the prepared material could be an efficient alternative material for future efforts in wastewater treatment.

Keywords:

• photocatalytic degradation
• polyurethane foam
• TiO₂
• adsorption
• bisphenol A
• montmorillonite