Visible light-induced photocatalytic degradation of gaseous toluene by Ce, S and N doped ionic liquid-TiO2

Abstract Ce, S and N doped TiO2 photocatalysts were synthesized through sol-gel method assisted by 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) and 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]). The as-prepared samples were characterized by means of Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope, X-ray diffraction, pore structure, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopic. The photodegradation of gaseous toluene was further investigated at visible light. Ionic liquid-TiO2 samples expose high specific surface area (about 100 m2 g−1), which are 5 times higher than bare TiO2. The results also showed that ionic liquid-TiO2 samples, especially in the introduction of [Bmim][Cl], present rather pure crystalline anatase with smaller crystallite size, higher hydrogen groups on surface and wider visible absorption bands. Moreover, tri-doped IL-TiO2 has superior photocatalytic degradation of gaseous toluene due to the above-mentioned characteristics, which is 5.7 times higher than bare TiO2.