Synthesis of novel BiVO4/Cu2O heterojunctions for improving BiVO4 towards NO2 sensing properties

Shouli Bai; Qiangqiang Li; Ning Han; Kewei Zhang; Pinggui Tang; Yongjun Feng; Ruixian Luo; Dianqing Li; Aifan Chen

doi:10.1016/j.jcis.2020.01.104

Synthesis of novel BiVO₄/Cu₂O heterojunctions for improving BiVO₄ towards NO₂ sensing properties

J Colloid Interface Sci. 2020 May 1:567:37-44. doi: 10.1016/j.jcis.2020.01.104. Epub 2020 Jan 31.

Authors

Shouli Bai¹, Qiangqiang Li¹, Ning Han², Kewei Zhang³, Pinggui Tang¹, Yongjun Feng¹, Ruixian Luo¹, Dianqing Li⁴, Aifan Chen¹

Affiliations

¹ State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Environmentally Harmful Chemicals Analysis, Beijing University of Chemical Technology, Beijing 100029, China.
² State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: nhan@ipe.ac.cn.
³ State Key Laboratory of Bio-Fibers and Eco-Textiles, Collaborative Innovation Center of Shandong Marine Biobased Fibers and Ecological Textiles, College of Materials Science and Engineering, Institute of Marine Biobased Materials, Qingdao University, Qingdao 266071, China. Electronic address: zhkw@qdu.edu.cn.
⁴ State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Environmentally Harmful Chemicals Analysis, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: lidq@mail.buct.edu.cn.

PMID: 32035392
DOI: 10.1016/j.jcis.2020.01.104

Abstract

To develop a high sensitive and low temperature NO₂ gas sensor, the novel BiVO₄/Cu₂O heterojunctions were synthesized by a modified metal organic decomposition method to decorate BiVO₄ nanoplates using Cu₂O nanoparticles for enhancement of BiVO₄ sensing performance to NO_2. The structure and morphology of BiVO₄, Cu₂O and BiVO₄/Cu₂O composites were characterized by XRD, SEM and TEM spectra. The results indicate that the BiVO₄/Cu₂O heterojunctions are composed of monoclinic BiVO₄ nanoplates with the thickness about 1.0-1.2 μm and 30-40 nm diameters of cubic Cu₂O nanoparticles. The gas-sensing tests display that the composite exhibits rapid and linear responses to low concentration NO₂ (from 100 ppb to 8.0 ppm), the highest response reaches 4.2 towards 4 ppm NO₂ at 60 °C and relative humidity of 28.3%, which is more than 2 times of pure BiVO₄ at the same condition. The enhanced sensing properties benefit from the novel p-n heterojunction between BiVO₄ and Cu₂O, which forms a depletion layer at the interface, leading to resistance increase of composites in NO₂. The work demonstrates the as-synthesized BiVO₄/Cu₂O is a promising sensing material to detect NO₂ gas.

Keywords: BiVO(4); Cu(2)O; Metal decomposition method; P-n heterojunction.