Enhanced ethanol sensing properties based on W-doped NiO flower-like microstructure: beneficial improvement from loose to dense morphology

Abstract In this paper, novel hierarchical undoped NiO and W-doped NiO microflowers were successfully synthesized via a facile hydrothermal route, and their sensing performance for ethanol was explored. Strikingly, the doping of W intervened the growth and assembly of NiO nanosheets to form different flower-like microstructures. The introduction of W caused beneficial morphological improvements from loose to dense microflower. Further ethanol sensing tests showed that the fabricated dense microflower based sensor possessed much higher response (60.15) and remarkable selectivity than that of the loose microflower at the optimal temperature of 300 °C. A plausible enhanced mechanism was proposed which demonstrated the improved properties may be ascribed to the large specific surface area and well-defined microstructure for gas adsorption and reaction.