Photocatalytic Degradation of Gaseous Formaldehyde by Polyvinyl Chloride Gauze Immobilized TiO2/Tourmaline Composites

Abstract

TiO2 was prepared by a sol-gel method and composited with tourmaline to improve the photocatalytic activity utilizing the spontaneous electric field of mineral. Then, the TiO2/tourmaline composites were supported onto Polyvinyl chloride (PVC) gauze to provide a convenient application for degradation of indoor formadehyde (HCHO) gas. The composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), automatic surface area and porosity analyzer (BET). The results showed that the grain size of TiO2 decreased after compositing with tourmaline, and the specific surface area of composites is much higher than that of the pure TiO2. The TiO2/tourmaline gauze exhibited excellent photocatalytic activity for the degradation of HCHO (100mg/m3), which was 5 times higher than that of TiO2 gauze. Moreover, the photocatalytic activity of the composite gauze was fully maintained after four photocatalytic cycles. The enhancement of photocatalytic activity was mainly due to the improvement of catalyst surface performances and capture of photoelectrons by electric field of tourmaline.