Construction of three-dimensional flower-like α-MoO3 with hierarchical structure for highly selective triethylamine sensor

Novel flower-like α-MoO3 with hierarchical structure was synthesized via a facile solvothermal route without any surfactant or template, and subsequent calcination at 400 °C in air for 2 h. The α-MoO3 flowers with the diameters about 3–5 μm consist of microrods with average diameters of 150–200 nm growing radially from the center of the hierarchical flower-like structure, and the microrods are assembled from nanoplates. The sensors based on α-MoO3 flowers are highly sensitive and distinctively selective to triethylamine (TEA). The response of this sensor to 100 ppm TEA attains 416 and the detection limit is 0.5 ppm at the operating temperature of 250 °C. The change of the surface status of α-MoO3 flowers before and after exposure to TEA at 250 °C was investigated by using XPS technique and the TEA sensing mechanism over α-MoO3 was proposed.