Interaction of carbon monoxide with PEDOT-PSS/zeolite composite: Effect of Si/Al ratio of ZSM-5 zeolite

Abstract

Composites with poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid), PEDOT-PSS, as the matrix containing ZSM-5 zeolites of various Si/Al ratios in the range of 23-280 at 20% (v/v) were fabricated to investigate the effect of Si/Al ratios on electrical conductivity sensitivity responses towards carbon monoxide (CO). The electrical conductivity responses of PEDOT-PSS/ZSM-5 composites were altered due to the available adsorption sites for CO molecules. The electrical conductivity sensitivity to CO increases with decreasing Si/Al ratios. The composites produce irreversible responses when replacing CO with nitrogen. The addition of ZSM-5 zeolites to the pristine PEDOT-PSS improves the electrical conductivity sensitivity of the composites by enhancing the interaction between PEDOT-PSS and CO gas. The composite of ZSM-5 zeolites with a Si/Al ratio equal to 23 gives the highest electrical conductivity sensitivity toward CO.