This paper reviews the recent progress in the synthesis and application of pillared transition metal oxides during the last decade, mainly concerning the synthetic methods, structures, physical properties and catalyti...This paper reviews the recent progress in the synthesis and application of pillared transition metal oxides during the last decade, mainly concerning the synthetic methods, structures, physical properties and catalytic appli-cations of the layered transition metal oxides pillared by inorganic oxides. The factors and their affecting regularity in the process of preparation, and some important results ob-tained in the catalytic application studies are summarized. Finally, a prospect on the potential new directions in this research area is also presented.展开更多
The microscopic process of oxidative etching of two-dimensional molybdenum disulfide(2D MoS_2) at an atomic scale is investigated using a correlative transmission electron microscope(TEM)-etching study.MoS_2 flakes on...The microscopic process of oxidative etching of two-dimensional molybdenum disulfide(2D MoS_2) at an atomic scale is investigated using a correlative transmission electron microscope(TEM)-etching study.MoS_2 flakes on graphene TEM grids are precisely tracked and characterized by TEM before and after the oxidative etching. This allows us to determine the structural change with an atomic resolution on the edges of the domains, of well-oriented triangular pits and along the grain boundaries. We observe that the etching mostly starts from the open edges, grain boundaries and pre-existing atomic defects.A zigzag Mo edge is assigned as the dominant termination of the triangular pits, and profound terraces and grooves are observed on the etched edges. Based on the statistical TEM analysis, we reveal possible routes for the kinetics of the oxidative etching in 2D MoS_2, which should also be applicable for other 2D transition metal dichalcogenide materials like MoSe_2 and WS_2.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 29903005 and 29573108) and the Modern Analysis Foundation of Nanjing University.
文摘This paper reviews the recent progress in the synthesis and application of pillared transition metal oxides during the last decade, mainly concerning the synthetic methods, structures, physical properties and catalytic appli-cations of the layered transition metal oxides pillared by inorganic oxides. The factors and their affecting regularity in the process of preparation, and some important results ob-tained in the catalytic application studies are summarized. Finally, a prospect on the potential new directions in this research area is also presented.
基金supported by the National Basic Research Program of China(2014CB932500,2015CB921004)the National Natural Science Foundation of China(51472215,51222202,61571197 and 61172011)the 111 project(B16042)
文摘The microscopic process of oxidative etching of two-dimensional molybdenum disulfide(2D MoS_2) at an atomic scale is investigated using a correlative transmission electron microscope(TEM)-etching study.MoS_2 flakes on graphene TEM grids are precisely tracked and characterized by TEM before and after the oxidative etching. This allows us to determine the structural change with an atomic resolution on the edges of the domains, of well-oriented triangular pits and along the grain boundaries. We observe that the etching mostly starts from the open edges, grain boundaries and pre-existing atomic defects.A zigzag Mo edge is assigned as the dominant termination of the triangular pits, and profound terraces and grooves are observed on the etched edges. Based on the statistical TEM analysis, we reveal possible routes for the kinetics of the oxidative etching in 2D MoS_2, which should also be applicable for other 2D transition metal dichalcogenide materials like MoSe_2 and WS_2.
