Cu-MOF-74-derived Cu2O/CuO-C nanocomposite as an effective chemiresistive sensor for detection of NO2 at room temperature

• Published in: Journal of alloys and compounds 2024-03, Vol.976, p.173074, Article 173074
• Main Authors: Li, Nan, Hu, Jing, Li, Jinjuan, Cheng, Miao, Wei, Tao, Liu, Qianqian, Wang, Ruirui, Li, Wanfei, Ling, Yun, Zhang, Yafei, Liu, Bo
• Format: Article
• Language: English
• Subjects: Cu-MOF-74; Cu2O/CuO nanocomposite; Gas sensing; NO2 detection
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2023.173074

We report a Cu2O/CuO-C nanocomposite which fabricated by thermal decomposition of Cu-based metal-organic framework (Cu-MOF-74) precursor. The attractive advantages of MOF-74 incorporating the abundant unsaturated (open) metal sites and excellent stability provide a guarantee for developing of efficient gas-sensing materials. After annealing, the material retains its skeleton structure and the surface area is greatly increased. The high porosity feature of the as-prepared Cu2O/CuO-C offers plentiful active sites for adsorption of gas molecules, thus ensuring high sensing performance. The results indicate that the Cu2O/CuO-C-based sensor exhibits high sensitivity (1.03–30 ppb NO2), good linear relationship and excellent selectivity to NO2 at room temperature (RT, 25 ℃). Notably, the theoretical detection limit of the as-prepared sensor is ∼7 ppb, which is significantly below the annual average NO2 concentration limit (40 ppm) imposed by China. The synergistic effect between CuO/Cu2O heterostructure and carbon, and the derived solid structure are considered as the main reason for high sensitivity and selectivity. In addition, the high oxygen vacancy concentration is also the key to ensure excellent gas sensitivity. This work provides a new choice for developing high performance room temperature NO2 gas sensor. [Display omitted] •The Cu-MOF-74-derived Cu2O/CuO-C was prepared by simple pyrolysis method.•Carbon film is wrapped around Cu2O/CuO to form a pomegranate-like structure.•The prepared sensor shows high response of 1.03–30 ppb at room temperature.•Excellent linear relationship and NO2 selectivity of the sensor was obtained.•Reasonable mechanism has been proposed to explain the sensing enhancement.