CuO/M(OH)₂ (M = Mg, Ca) heterostructures with in-situ oxygen vacancies enable room-temperature ultrahigh triethylamine sensing

  • Ruixiang Li
  • , Shu Chen
  • , Beibei Wang
  • , Xiaodan Wang*
  • , Xinyu Hu
  • , Sonia Estrade Albiol
  • , Cristian Fabrega Gallego
  • , Hao Shen*
  • , Chunhua Luo
  • , Hui Peng
  • , Hechun Lin*
  • *Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Room-temperature gas sensors are crucial for detecting toxic gases and volatile organic compounds (VOCs). Conventional metal oxide semiconductor (MOS)-based sensors, however, often require high-temperature operation and suffer from low sensitivity. Here, we present a one-step mini-mechanochemical synthesis of CuO/M(OH)2 (M = Mg, Ca) heterostructures that exhibit exceptional room-temperature sensing performance towards triethylamine (Et3N). Our results reveal a tenfold enhancement in the sensor response to Et3N compared to pristine CuO. This remarkable improvement is attributed to the in-situ formation of oxygen vacancies in CuO induced by the incorporation of M(OH)2, as evidenced by X-ray photoelectron spectroscopy (XPS), positron annihilation spectroscopy (PAS), and electron paramagnetic resonance (EPR). Notably, CuO/Mg(OH)2 demonstrates superior long-term stability, while CuO/Ca(OH)2 suffers from performance decay due to environmental carbonation. Furthermore, we developed a portable Et₃N analysis device based on the CuO/Mg(OH)2 sensor, which enables real-time monitoring with Wi-Fi capability and achieves an accuracy within 6 % error across a 1 to 100 ppm detection range. This study not only provides a cost-effective and scalable fabrication method for CuO-based gas sensors but also highlights the potential of CuO/M(OH)₂ in practical applications for environmental monitoring and food safety assessment.

Original languageEnglish
Article number167104
JournalChemical Engineering Journal
Volume521
DOIs
StatePublished - 1 Oct 2025

Keywords

  • CuO/M(OH) (M = Mg, Ca)
  • Enhanced sensing mechanism
  • In-situ formation of oxygen vacancies
  • Practical applications
  • Room-temperature gas sensors

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