State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology , 122 Luoshi Road, Wuhan 430070, P. R. China.
ACS Appl Mater Interfaces. 2017 Jan 25;9(3):2350-2357. doi: 10.1021/acsami.6b12819. Epub 2017 Jan 13.
Novel ramsdellite MnO hollow spheres consisting of closely stacked nanosheets (R-MnO-HS) were synthesized by a facile method. The R-MnO-HS sample was characterized with SEM, XRD, TEM, BET, XPS, diffusive reflectance UV-vis-IR absorption, etc. Remarkably, R-MnO-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 CO production rate) under the full solar spectrum irradiation is as high as 210.5 times higher than TiO(P25), a well-known benchmark photocatalyst for environmental cleanup. The excellent catalytic activity of R-MnO-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 TiO, 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 MnO. The solar light irradiation significantly promotes the lattice oxygen activity of R-MnO-HS, consequently resulting in a considerable enhancement in the thermocatalytic activity.
通过一种简便的方法合成了由紧密堆叠纳米片组成的新型锰铌空心球（R-MnO-HS）。R-MnO-HS 样品通过 SEM、XRD、TEM、BET、XPS、漫反射紫外可见红外吸收等进行了表征。值得注意的是，R-MnO-HS 在全太阳光谱或可见-红外照射下，甚至在红外照射下，对苯（一种致癌空气污染物）的净化具有高效的催化活性。其在全太阳光谱照射下的催化活性（初始 CO 生成速率）高达 210.5 倍，是一种用于环境净化的著名基准光催化剂 TiO(P25)。R-MnO-HS 的优异催化活性归因于其在整个太阳光谱区域内高效的热催化活性和光热转换，从而实现了高效的太阳能驱动热催化。非常有趣的是，一种新的光激活，与 TiO 上光激发电子和空穴引起的众所周知的光激活完全不同，极大地增强了太阳能驱动的热催化。通过在太阳光照射下和黑暗中使用 CO 程序升温还原（CO-TPR）以及密度泛函理论（DFT）计算，揭示了这种新光激活的起源：晶格氧活性在 MnO 的热催化中起着至关重要的作用。太阳光照射显著促进了 R-MnO-HS 的晶格氧活性，从而导致热催化活性的显著增强。
