title: UV-Visible-Infrared Light Driven Thermocatalysis for Environmental Purification on Ramsdellite MnO2Hollow Spheres Considerably Promoted by a Novel Photoactivation.
abstract: Novel ramsdellite MnO2hollow spheres consisting of closely stacked nanosheets (R-MnO2-HS) were synthesized by a facile method. The R-MnO2-HS sample was characterized with SEM, XRD, TEM, BET, XPS, diffusive reflectance UV-vis-IR absorption, etc. Remarkably, R-MnO2-HS exhibits highly efficient catalytic activity for the purification of benzene (a carcinogenic air pollutant) under the full solar spectrum or visible-infrared irradiation, even under the infrared irradiation. Its catalytic activity (initial CO2production rate) under the full solar spectrum irradiation is as high as 210.5 times higher than TiO2(P25), a well-known benchmark photocatalyst for environmental cleanup. The excellent catalytic activity of R-MnO2-HS is ascribed to its efficient thermocatalytic activity and its efficient photothermal conversion in the whole solar spectrum region, resulting in high efficient solar light driven thermocatalysis. Very interestingly, a novel photoactivation, which is completely different from the well-known photoactivation induced by photoexcited electrons and holes on TiO2, considerably enhances the solar light driven thermocatalysis. By use of CO temperature-programmed reduction (CO-TPR) under solar light irradiation and in the dark together with density function theory (DFT) calculations, the origin of the novel photoactivation was revealed: The lattice oxygen activity plays a crucial role in the thermocatalysis on MnO2. The solar light irradiation significantly promotes the lattice oxygen activity of R-MnO2-HS, consequently resulting in a considerable enhancement in the thermocatalytic activity.
authors.affiliation: State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology , 122 Luoshi Road, Wuhan 430070, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology , 122 Luoshi Road, Wuhan 430070, P. R. China.
authors.forename: Yuanzhi
authors.identifier: http://orcid.org/0000-0003-2305-950X
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology , 122 Luoshi Road, Wuhan 430070, P. R. China.
authors.forename: Mingyang
authors.initials: M
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology , 122 Luoshi Road, Wuhan 430070, P. R. China.
authors.forename: Min
authors.initials: M
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology , 122 Luoshi Road, Wuhan 430070, P. R. China.
authors.forename: Xiujian
authors.identifier: http://orcid.org/0000-0002-2517-2605
authors.initials: X
authors.lastname: Zhao
keywords: catalytic oxidation; nanosheets; photoactivation; ramsdellite MnO2; solar light driven thermocatalysis