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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Mater. | doi: 10.3389/fmats.2019.00195

Three-dimensional Fe3O4@reduced graphene oxide heterojunctions for high-performance room-temperature NO2 sensors

Cheng Zou1, Jing Hu2,  Yanjie Su1*, Feng Shao1, Zejun Tao1, Tingting Huo1, Zhihua Zhou1, Nantao Hu1,  Zhi Yang1, Eric Siu-Wai Kong1 and Yafei Zhang1
  • 1Shanghai Jiao Tong University, China
  • 2Suzhou University of Science and Technology, China

Metal oxide/reduced graphene oxide (RGO) heterojunctions have been widely used to fabricate room-temperature gas sensors due to large specific surface areas of RGO nanosheets and enhanced carrier separation efficiency at the interface. However, the sheet stacking of RGO nanosheets limits the full utilization of metal oxide/RGO heterojunctions. Herein, we demonstrate a high-performance room-temperature NO2 gas sensor based on 3D Fe3O4@RGO p-n heterojunctions with core-shell structure, which were synthesized by self-assembly method and further reduction. The effect of different Fe3O4/RGO ratios and the relative humidity on the sensing performances have been investigated. The experimental results suggest that the 3D Fe3O4@RGO sensor exhibits a good selectivity and high sensitivity of 183.1% for 50 ppm NO2, which is about 8.17 times higher than that of the pure 2D RGO sensor. When exposed to 50 ppb of NO2, the response value still reaches to 17.8%. This enhanced sensing performance is mainly ascribed to the formed heterojunctions and the larger surface area of RGO nanosheets. This 2D to 3D heterostructures strategy provides a general route to fabricate ultrahigh-performance room-temperature RGO-based gas sensors.

Keywords: Fe3O4@RGO heterojuntions, NO2 sensor, Electrostatic self-assembly method, heterostructures, three-dimensional core-shell structure

Received: 24 May 2019; Accepted: 29 Jul 2019.

Edited by:

Xiaogan Li, Dalian University of Technology (DUT), China

Reviewed by:

Lili Wang, Jilin University, China
Qiuxia Feng, Dalian Neusoft University of Information, China  

Copyright: © 2019 Zou, Hu, Su, Shao, Tao, Huo, Zhou, Hu, Yang, Kong and Zhang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Prof. Yanjie Su, Shanghai Jiao Tong University, Shanghai, 200240, Shanghai Municipality, China, yanjiesu@sjtu.edu.cn