Synthesis,characterization of WO3 nanopowder and its gas sensing properties

Nanosized WO₃ powders were synthesized from WCl₆ using chemical co-precipitation method. The WO₃ single crystal with mean particle size 68 nm was observed. Thick film resistors were prepared using screen printing technique for building ultra sensitive and selective gas sensors. The response at different temperature ranging from 100°C to 450°C were studied and presented for various gases. High sensitivity has been obtained towards H₂S, revealing the capability of the material to detect concentration as low as 10 ppm, upto the Threshold Limit Value (TLV). The results highlight that the nano-material can be adopted for the development of gas sensors with performances suitable for practical applications.