Synthesis, Characterization, and Gas-Sensor Application of WO[sub 3] Nanocuboids

Different sizes of single-crystal tungsten trioxide nanocuboids with monoclinic structure have been successfully synthesized via one-step hydrothermal procedure with and without the addition of cationic surfactant cetyltrimethylammonium bromide (CTAB) at . The as-synthesized products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, and UV-visible absorption spectra. The results showed that the size of the nanocuboids can be simply controlled by varying the molar ratio of CTAB to tungstenic acid. A solid-solution-solid mechanism of crystal growth was discussed. The as-prepared nanocuboids were further applied in gas sensors, displaying promising selectivity and high sensitivity to various organic gases such as petrol and ethanol.