■ Venue : Applied Engineering Department (W1-1) Multimedia Lecture Hall (1st Floor)
■ Host : Prof. Sang Ouk Kim
■ Abstract :
Since the discovery of graphene in 2004,1 conjugated two-dimensional (2D) organic networks have attracted immense interest due to their unusual electronic, optoelectronic, magnetic and electrocatalytic properties. In addition, their tunable structures and properties promise to offer more opportunities than graphene in various applications. However, even after years of intensive exploration of 2D materials in science and technology, facile and scalable methods capable of producing stable 2D networks with uniformly decorated heteroatoms with/without holes remain limited. To overcome these issues, new layered 2D organic networks have been designed and synthesized. They have uniformly distributed heteroatoms,2 holes with heteroatoms3 and transition metal nanoparticles in the holes.4 The structures were confirmed by scanning tunneling microscopy (STM). Based on the stoichiometry of the basal plane, they were, respectively, designated C3N, C2N and M@C2N (M = Co, Ni, Pd, Pt, Ru). Their electronic and electrical properties were evaluated by electrooptical and electrochemical measurements along with density-functional theory (DFT) calculations. Furthermore, robust three-dimensional (3D) cage-like organic networks have also been constructed and they show high sorption properties.5,6 The results suggest that these newly-developed 2D and 3D organic networks offer greater opportunities, from wet-chemistry to device applications.
 Novoselov, et al. Electric field effect in atomically thin carbon film. Science 2004, 306, 666.
 Mahmood, et al. Two-dimensional polyaniline (C3N) from carbonized organic single crystals. Proceedings of National Academy of Sciences, USA 2016, 113, 7414.
 Mahmood, et al. Nitrogenated holey two-dimensional structure. Nature Communications 2015, 6, 6486.
 Mahmood, et al. An efficient and pH-universal ruthenium-based catalyst for the hydrogen evolution reaction. Nature Nanotechnology 2017, 12, 441.
 Bae, et al. Forming a three dimensional porous organic network via explosion of organic single crystals in solid-state. Nature Communications 2017, 8, 159-Highlighted in Nature Nanotechnology 2018, 13, 4.9.
 Mahmood, et al. A robust 3D cage-like ultramicroporous network structure with high gas uptahe capacities. Angewandte Chemie International Edition 2018, DOI: 10.1002/ange.201800218.