Efficient photocatalytic degradation of gaseous formaldehyde by the TiO2/tourmaline composites

Graphical abstract: - Highlights: • The TiO{sub 2}/tourmaline composites were prepared by a sol–gel method. • The composites exhibited excellent photocatalytic activity and good stability. • The physicochemical property of tourmaline may be favor for the degradation of HCHO. • The mixed-phase of anatase and rutile TiO{sub 2} may be favor for the degradation of HCHO. - Abstract: The TiO{sub 2} supported tourmaline composites were prepared by a sol–gel method and used as a photocatalyst for the degradation of formaldehyde (HCHO). The composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N{sub 2} adsorption–desorption, Fourier transform infrared (FT-IR) spectroscopy and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The results indicate that the mixed-phase of anatase and rutile exists in the TiO{sub 2}/tourmaline composites. The specific surface area of the TiO{sub 2}/tourmaline composites is much higher than that of the pure TiO{sub 2}. The TiO{sub 2}/tourmaline composites exhibited excellent photocatalytic activity for the degradation of HCHO, which was 6 times higher than that of the pure TiO{sub 2}. Moreover, the excellent photocatalytic activity of the composites was fully maintained after five photocatalytic cycles, which may be attributed to the physicochemical property of tourmaline and themore » mixed-phase of anatase and rutile in the TiO{sub 2}/tourmaline composites.« less