Extremely efficient full solar spectrum light driven thermocatalytic activity for the oxidation of VOCs on OMS-2 nanorod catalyst

Abstract

The cryptomelane-type octahedral molecular sieve (OMS-2) nanorod catalysts with different concentration of oxygen vacancy exhibit strong absorption across the full solar spectra. The OMS-2 catalysts can efficiently transform the absorbed solar energy to thermal energy, resulting in a considerable increase of temperature up to 220°C. By combining the strong absorption across the full solar spectrum and the highly efficient thermocatalytic activity of the OMS-2 catalyst with high concentration of oxygen vacancies, full solar spectrum, visible-infrared, and infrared light driven thermocatalysis with extremely high efficiency are achieved. Under the irradiation of full solar spectrum, visible-infrared, and infrared light, the OMS-2 catalyst exhibits extremely high catalytic activity and excellent durability for the oxidation of organic pollutants such as benzene, toluene, and acetone. Under the full solar spectrum irradiation, the initial CO2 formation rate of the OMS-2 catalyst for benzene oxidation is 22.1 times larger than that of Bi2WO6/TiO2, a near-infrared photocatalyst reported recently. After the OMS-2 catalyst was recycled for 40 times, its catalytic activity remains unchanged. A novel mechanism of solar light driven thermocatalysis is proposed, and the reason why the OMS-2 catalyst with high concentration of oxygen vacancies exhibits the extremely high catalytic activity is discussed.