Mesoporous In2O3 with enhanced acetone gas-sensing property

• Mesoporous In2O3 has been synthesized using “container effect” nanocasting method.
• The In2O3 sensor exhibits enhanced acetone sensitivity and selectivity.
• The lowest acetone detection limit is 500 ppb, which benefits the diabetes diagnosis.
• The acetone gas-sensing mechanism was investigated and proposed.

Ordered mesoporous In2O3 with controlled morphology have been synthesized using “container effect” nanocasting method. The mesoporous In2O3 with larger mesopore size and smaller particle diameter exhibited improved sensitivity (response of 29.8 to 50 ppm of acetone at 300 °C), faster response and recovery times (0.7 and 14 s) and higher selectivity to acetone. The acetone detection limit is as low as 500 ppb, which favors the precise diagnosis of human diabetes. The enhanced acetone sensing performance benefits from the large surface area with enough sensing active sites, proper pore size for sufficient gas diffusion and small particle size for effective electron depletion.