3D structured TiO2-based aerogel photocatalyst for the high-efficiency degradation of toluene gas

Abstract

Photocatalytic technology is a “green”, environmentally friendly, energy-saving technology, which is considered to be an ideal method for removing volatile organic compounds (VOCs). At present, photocatalytic technology mostly uses powdered catalysts, which is not conducive to recycling and restricts the contact between the gas and catalyst. In this work, a three-dimensional (3D)-structured TiO₂-based aerogel with TiO₂ as the main body and all the components beneficial to photocatalysis was prepared for the first time. Under simulated sunlight irradiation, the toluene-removal rate of the Pt-loaded TiO₂ and reduced graphene oxide (RGO) composite aerogel (denoted as Pt–TiO₂/RGO aerogel, or PTA thereafter) was 60.47% higher than that of the pure RGO aerogel, and 56.03% higher than that of the bare TiO₂ nanofibers. The block-shaped composite aerogel could be easily recycled, and the C/C₀ of toluene using the recycled sample decreased by only 5.31% in the 5th run. The Pt–TiO₂/RGO composite aerogel had the highest photocatalytic degradation rate of toluene with a relative humidity (RH) of 60–80%, which is conducive to the purification of VOCs in high-humidity areas. The 3D aerogel enriches the contact between the solid photocatalyst and the toluene molecules, and also solves the problem of low adhesion between the catalyst and the carrier. This work provides a new perspective for the efficient removal of toluene gas by constructing a highly active 3D TiO₂ aerogel with an increased gas–solid reaction rate.