Synergistic enhancement of ammonia gas-sensing properties at low temperature by compositing carbon nanotubes with tungsten oxide nanobricks. (October 2019)

• Record Type: Journal Article
• Authors: Le, Xuan Vuong; Luu, Thi Lan Anh; Nguyen, Huu Lam; Nguyen, Cong Tu
• Is Part Of: Vacuum. Volume 168(2019)
• Publication Date: 2019-10
• Subjects: Carbon nanotube -- Tungsten oxide -- Nanocomposite -- Gas sensor -- Hole transfer; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2019.108861
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: Nanocomposite materials of stoichiometric WO3 nanobricks and commercial carbon nanotubes (CNTs) with different contents (0.5, 1.0 and 1.5 wt%) were simply fabricated by dispersing precursors in dimethylformamide. Stoichiometric WO3 nanobricks were directly synthesised by a hydrothermal method without any post-annealing treatment. At low temperatures, the nanocomposite-based sensors showed synergistically enhanced ammonia gas-sensing properties in comparison with CNT-based and WO3 nanobrick-based sensors. The 1.0 wt%-CNT-based sensor showed the most effective enhancement with 28-time higher response and 2-time shorter recovery times than the pristine CNT-based sensor. The limit of detection of the 1.0 wt%-CNT-based sensor could reach sub-ppm level detection (i.e. 150 ppb). The mechanism of this synergistic enhancement in composite materials was assigned to the hole transfer between the CNT surface and the inversion layer on stoichiometric WO3 nanobricks. Highlights: The synergistic enhancement of ammonia gas-sensing properties in CNT/WO3 nanocomposite-based sensors. The proof of hole-transfer between surface of CNTs and inversion layer on WO3 nanobricks in nanocomposite materials. Preparation high stoichiometric monoclinic WO3 nanobricks without any post-annealing process. The favorable properrties of nanocomposite-based sensors for low power-consumption ammonia gas sensor.