Highly sensitive acetone sensor based on conjugated polymer nanocomposites

A copolymer of pyrrole and o-aminophenol was synthesized by single step oxidative polymerization technique. Two different nanocomposites of copolymer with alpha-Fe2O3 and Co-alpha-Fe2O3 were prepared and acetone sensing property of both composites were studied at room temperature with different gas concentrations. The calculated sensitivity of the Co-alpha-Fe2O3 nanocomposite was 0.68 and alpha-Fe2O3 nanocomposite was 0.44. The sensitivity of prepared composites was higher than the pure polymer. The LOD of the alpha-Fe2O3 composite was found to be 0.13 ppm and Co-alpha-Fe2O3 composite was 0.37 ppm. Both the prepared composites have showed excellent selectivity with good repeatability for the acetone gas. The 20% Co-Fe2O3 containing nanocomposite sensor exhibited faster response time of 1.4 s and recovery time of 4.4 s towards the target gas and 15% alpha-Fe2O3 containing nanocomposite sensor exhibited the response time of 1.4 s and recovery time of 4.8 s for the acetone gas. The polymer and the nanocomposites have shown excellent repeatability for 7 cycles. The faster response of the sensor can be attributed to the increased number of oxygen vacancies on the sensor as well as the free O-H groups present in the polymer back bone.

Automated summary

A copolymer of pyrrole and o-aminophenol was synthesized using single step oxidative polymerization technique, and two nanocomposites were prepared. The sensitivity of the composites was higher than the pure polymer, and they exhibited good selectivity and repeatability for acetone gas. The nanocomposites containing Co-Fe2O3 and α-Fe2O3 showed faster response and recovery time towards the target gas. Both the polymer and nanocomposites demonstrated excellent repeatability.