Fabrication and optical hydrogen gas sensing property of hierarchical WO3 Porous/Nanowires film

The porous WO3 films and hierarchical WO3 porous/nanowires films were fabricated by the colloidal template method and solvothermal method, and Pt catalyst was loaded on films by sputtering. The porous WO3 films exhibited uniform and ordered porous structure with pore diameter of ∼1020, ∼810 and ∼360 nm. Morphology of hierarchical WO3 films showed that many nanowires with diameter of 20 ∼ 30 nm grew on the pore wall. The hierarchical Pt/WO3 films exhibited shorter response time to 4% H2 gas (24.8 s) at room temperature, about a third of that of porous Pt/WO3 films. And T% of hierarchical films can decrease by 65.1% at 1500 nm wavelength, twice higher than porous films (28.6%). This hierarchical structure combines the adjustable pore size and high aspect ratio nanowires, which provides a new reference for the structure design of WO3 based sensors.