Fabrication of ZnO quantum dots@SnO2 hollow nanospheres hybrid hierarchical structures for effectively detecting formaldehyde

• Published in: Sensors and actuators. B, Chemical Vol. 318; p. 128222
• Main Authors: Sun, Yongjiao, Yang, Haoyue, Zhao, Zhenting, Suematsu, Koichi, Li, Pengwei, Yu, Zhichao, Zhang, Wendong, Hu, Jie
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.09.2020; Elsevier Science Ltd
• Subjects: Ammonia; Benzene; Formaldehyde; Gas sensor; Gas sensors; Heterojunctions; Hybrid hierarchical structures; Linearity; Nanospheres; Porosity; Quantum dots; Recovery time; SnO2 hollow nanospheres; Structural hierarchy; Tin dioxide; Toluene; VOCs; Volatile organic compounds; Zinc oxide; ZnO quantum dots; SnO2 hollow nanospheres; Hybrid hierarchical structures; Gas sensor; ZnO quantum dots; Formaldehyde
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2020.128222

•ZnO QDs@SnO2 HNSs hybrid hierarchical structures were fabricated by modifying ZnO quantum dots on the surface of SnO2 hollow nanospheres.•ZnO QDs@SnO2 HNSs hybrid hierarchical structures shows selective response to formaldehyde among four kinds of confusable indoor VOCs.•ZnO QDs@SnO2 HNSs hybrid hierarchical structures exhibited superior sensing performance to formaldehyde which could be attributed to the special structure and the heterojunctions between ZnO and SnO2. The ZnO quantum dots modified SnO2 hollow nanospheres (ZnO QDs@SnO2 HNSs) hybrid hierarchical structures were fabricated by modifying ZnO QDs on the surface of SnO2 HNSs using precipitation and hydrothermal method. The gas sensors based on ZnO QDs, SnO2 HNSs and ZnO QDs@SnO2 HNSs present superior sensing properties to formaldehyde compared with three other typical indoor volatile organic compounds (VOCs, including formaldehyde, toluene, benzene and ammonia). In particular, the ZnO QDs@SnO2 HNSs based sensor exhibits high response (36.5–50 ppm), good linearity (1−1000 ppm), rapid response/recovery time (9 s/ 10 s), ultra-low limit of detection (LOD, 5 ppb) and excellent long-term stability. The ZnO QDs@SnO2 HNSs hybrid hierarchical structures not only ensure the porosity but also create lots of heterojunctions, which is benefit for improving the gas sensing properties of a gas sensor.