Defect-original room-temperature hydrogen sensing of MoO3 nanoribbon: Experimental and theoretical studies

SENSORS AND ACTUATORS B-CHEMICAL

卷:260

Article

Yang, Shulin^1,2  Wang, Zhao¹  Hu, Yongming¹  Cai, Yaxuan¹  Huang, Rui¹  Li, Xiaokang¹  Huang, Zhongbing¹  Lan, Zhigao²  Chen, Wanping³  Gu, Haoshuang¹ 

[1] Hubei Univ, Hubei Key Lab Ferro & Piezoelect Mat & Devices, Hubei Collaborat Innovat Ctr Adv Organ Chem Mat, Fac Phys & Elect Sci, Wuhan 430062, Hubei, Peoples R China

[2] Huanggang Normal Univ, Sch Elect Informat, Huanggang 438000, Peoples R China

[3] Wuhan Univ, Sch Phys & Technol, Wuhan 430072, Hubei, Peoples R China

关键词: Hydrogen sensor;    MoO3;    Nanoribbon;    DFT;    Defect;   

DOI  :  10.1016/j.snb.2017.12.166

来源: Elsevier

【 摘 要 】

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.

【 授权许可】

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