Ultrathin mesoporous Co3O4 nanosheets with excellent photo-/thermo-catalytic activity

Abstract

Ultrathin mesoporous Co₃O₄ nanosheets on a stainless steel mesh (SS–Co₃O₄) have been synthesized through an electrochemical deposition method. The SS–Co₃O₄ catalyst exhibits high photothermal performance, resulting in a considerable increase of temperature above the light-off temperature for VOC oxidation. Aerobic oxidations of propylene and propane under simulated sunlight were selected as probe reactions to explore the photo-/thermo-catalytic (PTC) activity. The results show that SS–Co₃O₄ with only 7 mg of Co₃O₄ grown on the substrate possesses superior PTC activity, which merely occurs around the directly grown SS–Co₃O₄ rather than the Co₃O₄ coated SS. The combined properties of SS–Co₃O₄ such as the ultrathin two-dimensional shape, foam-like porous inside architecture, and supported metal substrate could lead to the integrative advantages of the maximum utilization of photothermal conversion, more catalytically active sites, and enhanced amount and mobility of surface lattice oxygen species, resulting in excellent PTC activity of SS–Co₃O₄. This work provides insights into the rational design of monolith catalysts for the solar driven environmental purification and suggests new ideas toward the overall utilization of solar energy.