Highly sensitive and rapid chemiresistive sensor towards trace nitro-explosive vapors based on oxygen vacancy-rich and defective crystallized In-doped ZnO

• Published in: Sensors and actuators. B, Chemical Chemical, 2017-06, Vol.244, p.983-991
• Main Authors: Ge, Yuru, Wei, Zhong, Li, Yushu, Qu, Jiang, Zu, Baiyi, Dou, Xincun
• Format: Article
• Language: English
• Subjects: Crystal defects; Crystallization; Crystals; Detection; Explosives detection; Gas detectors; Gas sensing; Indium doping; Lattice vacancies; Nanoparticles; Nitro-explosive vapors detection; Organic chemistry; Oxygen; Oxygen vacancies; RDX; Recovery time; Response time; Semiconductor doping; Sensors; Vacancies; Zinc oxide; Zinc oxides; ZnO nanoparticles
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.01.092

[Display omitted] •The oxygen vacancy rich and defective In doped ZnO NPs were synthesized via a sol-gel route and post-annealing process for defect regulation.•The In-ZnO NPs exhibit great sensitivity and real-time characteristics for the room-temperature detection of trace nitro-explosive vapors.•The enhancement of sensing performance is attribute to the creation of abundant oxygen vacancies and defective crystalline state. In order to sensitively detect trace nitro-explosive vapors, the sensing properties of ZnO nanoparticles (NPs) are boosted by tailoring the doping level of indium (In). With the introduction of In, the shape of the ZnO NPs changes from sphere with grain size of 55.2±9.6nm to irregular NPs with a reduced size. The sensing performances of sensors towards room-temperature saturated nitro-explosive vapors generally increase firstly and then decrease, peaking at an atomic ratio of 1.29% (corresponding to 5% In in the precursor). The 5% In-doped ZnO nanoparticle-based sensor exhibited remarkably enhanced responses towards trace nitro-explosive vapors, including TNT of 9ppb, DNT of 411ppb, PNT of 647ppb, PA of 0.97ppb and RDX of 4.9ppt at room temperature. For instance, compared with ZnO, the responses to nitro-explosive vapors were increased from 22.2, 8.5, 2.9, 4.9 and 9.8% to 54.7, 52.9, 57.2, 58.3 and 47.4%, respectively. Furthermore, much shorter response time (