Controllable assembly of corn cob-like h/ γ-WO 3 hierarchical structure for enhanced sensitive detection of dibutylamine vapor

It is urgent to fabricate a chemiresistive sensor for sensitive detection of hazardous dibutylamine (DBA) owing to the lack of relevant report. Herein, small -size (NH 4 ) 0.33 WO 3 nanorod arrays were grown on h -WO 3 nanorod skeleton through solvothermal method. Subsequently, the above precursors were calcined in air to controllably prepare two corn cob -like h/ gamma-WO 3 hierarchical structures, and the effects of phase transition and calcination temperature on gas -sensing performances were also explored. Among, h/ gamma-WO 3 -5 obtained by calcining precursor at 500 degrees C possesses good crystallinity, wide pores, large specific surface area and small band gap, which contribute to electron migration and generation of more adsorbed oxygen species. Under the catalytic synergism of surface W 6+ Lewis acid, h/ gamma-WO 3 -5 achieves the selective detection of metal oxide -based sensor to DBA vapor for the first time. At the operating temperature of 252 degrees C, h/ gamma-WO 3 -5 sensor realizes high response of 105 -100 ppm DBA vapor, which is 1.52 and 3.65 times larger than those of corn cob -like h/ gamma-WO 3 -4 (calcinated at 400 degrees C) and h -WO 3 nanorods. Meanwhile, it has fast response rate, low detection limit, and humidity resistance. In addition, O 2 -TPD, XPS and GC -MS techniques were used to explore its sensing mechanism to trace DBA in detail.