Highly Sensitive and Selective Organic Gas Sensors Based on Nitrided ZSM-5 Zeolite

Abstract

For next-generation gas sensors, conductive polymers have strong potential for overcoming the existing deficiencies of conventional inorganic sensors based on metallic oxides. However, the signal of organic gas sensors is inferior to that of inorganic metal oxide gas sensors because of organic gas sensors’ poor charge carrier transport. Herein, the combination of an organic transistor-type gas sensor and a zeolite with strong gas-adsorbing properties is proposed and experimentally demonstrated. Among the various investigated zeolites, ZSM-5 with ∼5.5 Å pore openings enhanced the adsorption for small gas molecules when combined with a polymer active layer, where it provided a pathway for gas molecules to penetrate the zeolite channels. Moreover, nitrided ZSM-5 (N-ZSM-5) enhanced the sensing performance of NO2 molecules selectively because N in the N-ZSM-5 framework strongly interacted with NO2 molecules. These results open the possibility for zeolite-modified organic gas sensors that selectively adsorb target gas molecules via heteroatoms substituted into the zeolite framework.

Enhanced Gas Sensing Characteristics of a Polythiophene Gas Sensor Blended with UiO‐66 via Ligand Functionalization

“…Moreover, the sensitivity of the U-NH 2 /P3HT blend film to 100 ppm NO 2 gas was twice that of the home P3HT film (Figure 4i). Indeed, the sensor proposed in this study demonstrates superior performance in terms of high-sensitivity behavior compared to NO 2 gas sensors presented in other studies [33][34][35][36][37][38][39][40][41][42][43][44][45] (Table S1, Supporting Information).…”

Additive engineering for high-performance polythiophene gas sensors incorporating functional amine additive with strong binding energy for NO2

“…21,22 In a previous study, nitrided zeolites in conductive polymers were investigated for selective NO 2 adsorption. 23,24 Nitrogen has robust potential as a functional site for adsorbing NO x molecules. 25 However, fabricating a homogeneous blend film is challenging due to the difficulty in achieving adequate dispersion of inorganic porous materials in the polymer matrix, which results in low reproducibility of the device performance.…”