Poly-triphenylene membrane: A multifunctional two-dimensional porous carbon framework with ultra-high carrier mobilities and potassium ion storage capacity

Abstract

The development of multifunctional two-dimensional (2D) carbon-based materials with novel, excellent properties and high performance is a challenge. By using density functional theory methods, a novel 2D planar and porous carbon material 2D-C18H6, which is a poly-triphenylene membrane composed of triphenylene molecules, is systematically investigated. The computational results confirm that the 2D-C18H6 structure has good lattice dynamics stability and high thermal stability. 2D-C18H6 displays great gas separation ability with high selectivity and high diffusive flux of He and H2 from other gas molecules, due to its dense pores of proper size in the structure. It is a semiconductor with a direct band gap of 2.36 eV and ultra-high carrier mobilities along both a and b directions, up to 7.6 × 104 cm2V−1s−1. The adsorption and migration of K atoms on 2D-C18H6 monolayer indicate it exhibits ultra-high theoretical specific capacity of 1449 mAh·g−1, low voltage of 0.285–0.024 V and low migration barrier of 0.125 eV. Possessing various excellent properties, 2D-C18H6 monolayer has potential applications in electronic device semiconductors, potassium ion battery anode materials, photocatalytic hydrogen evolution materials and gas separation membranes.