Facile Synthesis of Metal-Impregnated Sugarcane-Derived Catalytic Biochar for Ozone Removal at Ambient Temperature

Abstract

This study presents the first attempt at employing catalytic biochar to remove ground-level ozone at ambient temperature. With the increase in human activity, ozone has become a critical inorganic pollutant that needs to be addressed, using more sustainable methods. Fe- and Mn-impregnated catalytic biochars were prepared from a sugarcane feedstock via the wet impregnation method and pyrolysis at various temperatures, where the optimum value was determined to be 550 °C. The metal-impregnated biochar samples demonstrated enhanced surface areas and pore volumes compared with the pristine biochar (SCB550), resulting in improved ozone-adsorption capacity. SCB550-Fe exhibited an ozone-adsorption capacity of 52.1 mg/g at 20 ppm, which was approximately four times higher than that of SCB550. SCB550-Fe demonstrated superior ozone-removal performance compared to SCB550-Mn; 122 mg/g capacity as opposed to 116.2 mg/g at 80 ppm, respectively. Isothermal and kinetic modeling are also presented to suggest a plausible mechanism of ozone removal by catalytic biochar. This includes physical adsorption, complexation, electrostatic interaction, and electron transfer during the redox reaction between ozone and metals. Overall, this study should provide preliminary insights into ozone removal using biochar and promote further research regarding material optimization and kinetic studies.