Defect-original room-temperature hydrogen sensing of MoO3 nanoribbon: Experimental and theoretical studies
Defect-original room-temperature hydrogen sensing of MoO3 nanoribbon: Experimental and theoretical studies
复制标题
MoO3纳米带的缺陷原始室温氢传感：实验和理论研究
DOI：
10.1016/j.snb.2017.12.166
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发表时间：
2018-05-01
影响因子：
8.4
通讯作者：
Gu, Haoshuang
中科院分区：
文献类型：
--
作者：
Yang, Shulin;Wang, Zhao;Gu, Haoshuang
氢能领域的快速发展激发了低温氢传感器传感性能的提高。有效的实验研究和模拟计算对于理解金属氧化物氢传感器的传感机理和提高其传感能力具有重要意义。在这项工作中，我们采用水热法制备了超长正交MoO3纳米带。在光学显微镜下，通过简单的工艺组装了基于单个MoO3的氢传感器。在不同的气氛下退火可以调节纳米带中Mo5+的浓度。在Mo5+浓度为25%的H-2气氛下退火的纳米带对1000 ppm H-2的传感器响应比在真空或O-2气氛下退火的纳米带高11.23。我们对不同背景大气的气敏测试结果表明，氧的种类与氢的传感性能密切相关。计算研究表明，无论是否存在缺陷，纯氢分子都不能吸附在MoO3（010）表面。氧分子可以从MoO3材料中捕获电子，在具有末端氧空位的MoO3（010）表面形成化学吸附物质。注入的H-2气体可以与预吸附的O-2（-）反应生成H2O，将电子释放回传感材料。我们的理论结果与实验结果吻合得很好。(C) 2017 Elsevier B.V.版权所有
Rapid development in the hydrogen energy sector inspires improvement in the sensing properties of low-temperature hydrogen sensors. Both effective experimental researches and simulated calculations are highly beneficial in understanding the sensing mechanism of metal-oxide hydrogen sensors and enhancing their sensing capabilities. In this work, we prepare ultra-long orthorhombic MoO3 nanoribbons using a hydrothermal method. Hydrogen sensors based on single MoO3 are assembled under an optical microscope through a simple process. The concentration of Mo5+ in the nanoribbons can be adjusted by annealing in different atmospheres. The nanoribbon annealed in H-2 atmosphere with Mo5+ concentration of 25% presents a higher sensor response of 11.23 towards 1000 ppm H-2 than those annealed in a vacuum or an O-2 atmosphere. Our gas-sensing testing results for different background atmospheres reveal that the oxygen species are closely related to the hydrogen sensing performance. The calculated researches show that pure hydrogen molecules cannot be adsorbed on MoO3 (010) surfaces both with and without defects. Oxygen molecules can capture the electrons from the MoO3 material to form chemisorbed species on the MoO3 (010) surface with terminal oxygen vacancies. The injected H-2 gas can react with the pre-adsorbed O-2(-) to form H2O, releasing electrons back to the sensing material. Our theoretical results are in good agreement with those of the experimental investigation. (C) 2017 Elsevier B.V. All rights reserved.