Modulation of ZnFe2O4/ZnO heterostructure for enhanced triethylamine sensing performance

• Published in: Sensors and actuators. B, Chemical Chemical, 2024-06, Vol.408, p.135580, Article 135580
• Main Authors: Yang, Xuan-Yu, Zhang, Wen-Jie, Shi, Ya-Tong, Yue, Li-Juan, Xie, Ke-Feng, Jin, Gui-Xin, Fang, Shao-Ming, Zhang, Yong-Hui
• Format: Article
• Language: English
• Subjects: 2D nanosheets; Gas sensors; In-plane heterojunction; Triethylamine
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2024.135580

The emerging in-plane heterostructures exhibit unique structure properties, attracting considerable attention in the gas sensors. However, the insight of the structure difference between in-plane and out-plane heterojunctions as well as the structure-activity relationship are still ambiguous. Herein, a novel in-plane ZnFe2O4/ZnO heterojunction (ZnFe2O4/ZnO-1) is designed for the efficient detection of triethylamine, which exhibits superior sensing performance with high selectivity and fast response/recovery, and the sensing response (Ra/Rg=424.07, 50 ppm) is 3.66 folds higher than the out-plane ZnFe2O4/ZnO heterojunction (ZnFe2O4/ZnO-2). Moreover, multiple structure analysis and DFT calculations reveal numerous grain boundaries form in ZnFe2O4/ZnO-1, and the lattice strain, d-band electronic structure, surface oxygen species as well as the surface acidity exhibit great difference with ZnFe2O4/ZnO-2. Notably, the formation of in-plane heterojunctions facilitates the generation of abundant surface O2- (ad) species and large amounts of Lewis acid sites, as well as the upshift of d-band center, which contributes to the enhanced triethylamine sensing performance. Our work illustrates the structure-activity relationship between in-plane and out-plane heterojunctions, and paves the way for the design of novel heterostructure for detecting harmful volatile organic compounds. •The in-plane ZnFe2O4/ZnO heterostructures have been successfully synthesized.•The in-plane material exhibits superior sensing performance to TEA at 120 °C.•The structural differences between in-plane and out-plane are investigated.•The structure-activity relationship of ZnFe2O4/ZnO-1 to TEA sensing is illustrated.•The surface O2-(ad) species, Lewis acid and the upshift of d-band center contribute to the sensing performance.