Dai Haiwen, Rath Ashutosh, Hearn Yu Shu, Pennycook Stephen J, Chua Daniel H C
Department of Material Science and Engineering , National University of Singapore , 9 Engineering Drive 1 , Singapore 117575.
J Phys Chem Lett. 2018 Dec 20;9(24):7185-7191. doi: 10.1021/acs.jpclett.8b03437. Epub 2018 Dec 17.
Reduced molybdenum oxide, generally MoO, becomes increasingly metallic as the oxygen level decreases during the reduction of MoO to MoO. Its interesting properties have recently intrigued research on MoO in electrical and electrochemical areas. Lacking effective tools to control the oxygen level is one of the research difficulties for MoO. Herein, we report facile temperature-controlled synthesis of triangular MoO and square MoO. The triangular and square flakes showed metallic behavior with conductivity as high as ∼940 and ∼28 S/cm in DC measurement, respectively. The decrease in oxygen level from MoO to MoO affected the density of states mapped in Mo 4d orbitals, leading to higher conductivity for triangular MoO. Further Mott-Schottky analysis on MoO regrown on carbon fiber paper (CFP) revealed hole mobility of 10-10 cm V s. The hole carriers at high frequencies are attributed to potential oxygen acceptors, and molybdenum vacancies resulted from limited reduction power of hydrogen.
还原氧化钼，一般为MoO，在MoO还原为MoO的过程中，随着氧含量的降低，其金属性越来越强。其有趣的性质最近引发了在电学和电化学领域对MoO的研究。缺乏控制氧含量的有效工具是MoO研究的困难之一。在此，我们报道了通过简便的温度控制合成三角形MoO和方形MoO。三角形和方形薄片表现出金属行为，在直流测量中电导率分别高达约940和约28 S/cm。从MoO到MoO氧含量的降低影响了Mo 4d轨道中映射的态密度，导致三角形MoO具有更高的电导率。对在碳纤维纸（CFP）上再生的MoO进行的进一步莫特-肖特基分析显示空穴迁移率为10-10 cm V s。高频下的空穴载流子归因于潜在的氧受体，以及氢气还原能力有限导致的钼空位。
