TiO₂ Coated-Asphalt Buton Photocatalyst for High-Performance Motor Vehicles Gas Emission Mitigation

Gas emission from motor vehicle has become the origin of many serious issues including health and air-quality, green house effect, and other environment issues. While motor vehicle manufacturers have set a particular standard of gas emission and motor vehicle aging, usage has contributed to the increase of hazardous gas emission from vehicles. Therefore, developing a special material that can adsorb the emitted gases should be continuously demonstrated. This paper reports the fabrication of a high-performance material, i.e., asphalt naturally found in Buton Island, Indonesia (asbuton), composited of anatase TiO₂ (ATi), for application in gas emission reduction, such as carbon monoxide (CO), carbon dioxide (CO₂), and other hydrocarbon gases (HC). ATi was prepared by coating the pre-extracted asbuton with anatase TiO₂ sol-gel via a spray-coating technique and annealed at 120 °C for 3 h. We found that the CO, CO₂, and HC gases can be effectively adsorbed by the ATi adsorbent as high as 600, 1500, and 760 ppm, respectively, for exposure time of only 90 s each. The gas adsorption on the ATi obeys Langmuir and Freundlich isotherms. The maximum gas adsorption capacity was found to be as high as 95,238 and 2348 ppm (for CO₂ and HC, respectively). The availability of abundant –OH active ligand on Si–OH and Ti–OH and highly porous structure, as judged from the FTIR and SEM analysis results, is assumed as the key reason for the high adsorption capacity of the ATi. The ATi should find a potential application in motor vehicle gas emission and air pollutant mitigation.