Synergistic enhancement of triethylamine sensing performances via oxygen vacancy-rich Co-doped MnO 2 @MnCo 2 O 4.5 nanorods/nanosheets

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2024-08, Vol.12 (32), p.12623-12634
• Main Authors: Hu, Xiaobing, Chen, Hao, Zhang, Kaibin, Tian, Dongxia, Cao, Yi, Zhu, Zhigang
• Format: Article
• Language: English
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/D4TC02453B

The presence of oxygen vacancies in p-type metal–oxide semiconductors significantly boosts gas-sensing performance. Despite this, the current literature lacks extensive studies on inducing oxygen vacancies in manganese-based oxides to enhance their intrinsic activities. Thus, developing a simple and efficient synthetic method to generate abundant oxygen vacancies in manganese-based oxides is essential. In this study, we achieved a straightforward transformation of Co-doped-MnO 2 into MnCo 2 O 4.5 nanosheets with plentiful oxygen vacancies by reducing then with NaBH 4 solution at room temperature. This uncomplicated process effectively produced MnCo 2 O 4.5 nanosheets with numerous oxygen vacancies, which markedly improved the gas-sensing properties. The hierarchical Co-doped-MnO 2 @MnCo 2 O 4.5 nanorods/nanosheets nanocomposite, benefiting from the Co doping and reduction strategy, demonstrated superior gas-sensing performance compared to pristine MnO 2 nanowires. Specifically, the sensor's response based on Co-doped-MnO 2 @MnCo 2 O 4.5 to 50 ppm TEA gas increased by 340% at an optimal operating temperature of 170 °C, which is 2.7 times higher than that of pristine MnO 2 . This exceptional performance is attributed to the synergistic effect of oxygen vacancies and active sites within the hierarchical nanocomposite structure.