Papers by Author: Li Yin

Abstract: Hollow-spherical WO₃ nanocrystals were obtained by calcining an organic-inorganic W-C precursor containing C and W in a microwave oven or in a conventional muffle furnace, and the W-C precursor hybrid precursor was synthesized via a hydrothermal method. The samples were characterized by XRD, TG-DTA, FTIR and SEM. The morphologies of the WO₃ samples obtained by conventionally heating (C-WO₃) and microwave-assisted heating (M-WO₃) were compared. The average diameter and shell thickness of C-WO₃ hollow spheres is about 450 and 200 nm, respectively. The average diameter and shell thickness of M-WO₃ hollow spheres is about 500 and 50 nm, respectively. The M-WO₃ has a loose and multilayered shell, and their nanoparticles are smaller than those of C-WO₃. The improved structure of M-WO₃ is due to shorter heating time and the unique heating style in a microwave oven. The gas-sensing performances of the WO₃ sensors were investigated. The M-WO₃ sensor has better response to ethanol vapors than the C-WO₃.