Colloidal synthesis of tungsten oxide quantum dots for sensitive and selective H2S gas detection.

Tungsten oxide (WO 3 ) has been intensely investigated as an important gas-sensing materials. Here the sensitive and selective H 2 S gas sensors based on WO 3 quantum dots that were synthesized via a colloidal process using WCl 6 ethanol solutions mixed with oleic acid and oleylamine were demonstrated. The solution processability of the colloidal WO 3 quantum dots enabled a room-temperature sensor fabrication without high-temperature sintering. The optimal sensor response toward 50 ppm of H 2 S is 57 with the response time of 47 s, and the response was fully recoverable upon H 2 S release at 80 °C. The sensing mechanism was discussed by using first-principles calculation based on density functional theory (DFT). Their highly sensitive and fast response at lower operating temperature, combined with the benefit of ease fabrication, make the colloidal tungsten oxide quantum dots highly attractive for the construction of low cost gas sensor with reduced power consumption. [ABSTRACT FROM AUTHOR]