Facile photo-driven strategy for the regeneration of a hierarchical C@MnO2 sponge for the removal of indoor toluene

Abstract Herein, MnO 2 -decorated carbon sphere was synthesized and loaded onto a commercial sponge (Sponge@C@MnO 2 ). The integrated Sponge@C@MnO 2 exhibited wide pore distributions ranging from macropores to micropores, permitting multiple reflections and scattering of light inside their pore channels via the increase of light traveling paths, thus, promoted the light-harvesting efficiency. Under the irradiation of xenon lamp, the surface temperature could reach as high as 130.1 °C within 30 s due to the unique photothermal property of carbon sphere. This temperature was sufficiently high enough to trigger the regeneration of adsorbed toluene. In addition, the introduction of outer shell MnO 2 on the carbon sphere led to the dramatic decrease in the desorbed content of toluene via its direct oxidation. Furthermore, the porous structure of the sponge substrate exhibited a low pressure drop (4.5 Pa at retention time of 1.2 s), possibly providing practical applications for the purification of pollutated indoor air. This work illustrated a novel strategy for the efficient utilization of solar energy via the construction of a hierarchical material, paving a way for the design of a facile photothermal regeneration method for the removal of indoor toluene.