[en] In this paper, a novel TiO₂-SiO₂ aerogel nanocomposite absorbent was successfully synthesized using the sol-gel and ambient pressure drying method, and its photocatalytic degradation effects on automobile exhaust were investigated for the first time. The microstructures and properties of the Nano TiO₂-SiO₂ aerogels were characterized using various methods, including x-ray Diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area analysis, Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) and Fourier Transform Infrared Spectroscopy (FT-IR). The exhaust purification tests were conducted in a self-developed instrument to investigate the degradation effects of Nano TiO₂-SiO₂ aerogels on automobile exhaust through degradation rate. Experimental results showed that the Nano TiO₂-SiO₂ aerogels had a good photocatalytic degradation effect on automobile exhaust, and the degradation rates of CO, CO₂, HC and NOx were 1.3%, 1.5%, 3.2% and 34.4%, respectively. The well-designed microstructure makes the Nano TiO₂-SiO₂ aerogels a stable photocatalytic material with high specific surface area and big average pore size, which has promising applications in environmental treatment. (paper)