| Electronic Structure and Energy Applications of Layered Materials Tekalign Terfa Debela1; Hafiz Ghulam Abbas2; Hong Seok Kang3; 1JEONJU UNIVERSITY, Jeonju, South Korea; 2CHONBUK NATIONAL UNIVERSITY, Jeonju, South Korea; 3JEONJU UNIVERSITY, Chonju, South Korea; PAPER: 396/Chemistry/Keynote (Oral) SCHEDULED: 12:35/Thu. 24 Oct. 2019/Aphrodite A (100/Gr. F) ABSTRACT: Based on a combination of various first-principles methods, we propose various kinds of layered materials. One is tetragonal GeP2, which has optimal band offset for photocatalyzed CO2 decomposition in wide pH range.[1] The second one TeSe2, which exhibits phase polymorphism, phase transition on charge doping, ferroelectricity, and interesting spin texture.[2,3] I also describe a series of my recent collaborations with an experimental group. First, combined experimental and theoretical effort is described for an efficient photoelectrochemical (PEC) water splitting of p-GeAs/n-Si heterojunction based on the band alignment, buildup of space charge in the junction, and the band bending of the n-Si at the electrolyte interface.[4] Second, our extensive DFT calculation complemented by analysis of charge transfer, band structure analysis, and reaction path for Volmer-Heyrovsky reactions give a deep insight into our experimental results, which has shown that the 1T'-phase guest-intercalated MoS2/WS2 nanosheets synthesized by one-step hydrothermal reaction exhibit excellent stability as well as higher catalytic activity toward the hydrogen evolution reaction at specific guest concentrations.[5-7] Finally, our extensive ab initio molecular dynamics simulations not only reproduce collaborative experimental voltage-charge capacity curves for WS2@graphite and WS2@nitrogen-doped graphite composites in lithium ion battery but also gives us a detailed picture on the structural evolution in the charge-discharge process.[8] References: [1] F. Shojaei, J. R. Hahn, H. S. Kang, J. Mater. Chem. A 5 (2017), 22146. (Selected as cover article) [2] T. T. Debela, H. S. Kang, J. Mater. Chem. C 6 (2018), 10109. (Selected as the Cover Article) [3] T. T. Debela, S. Liu, J.-H. Choi, H. S. Kang, in submission. [4] C. S. Jung et al. J. Mater. Chem. A. 6 (2018), 6, 9089. [5] I. H. Kwak et al, J. Mater. Chem. A, 6 (2018) 5613. [6] I. H. Kwak et al, J. Mater. Chem. A, 7 (2019) 2334. [7] I. H. Kwak et al, J. Mater. Chem. A, Advanced Article. [8] T. T. Debela et al. ACS Appl. Mater. Interfaces 10 (2018), 37928. |
