FeN4-embedded warped nanographene as a potential candidate for scavenging and detecting sulfur-based gases: A DFT study

Abstract

To bringing more safety to the working and living environment, effectively monitoring and purification of hazardous sulfur-based gases (H2S, SO2, SO3, SOF2 and SO2F2) are strongly required. In this study, the sensing mechanism of pristine and four-nitrogen coordinated iron (FeN4) embedded warped nanographene (WNG) towards sulfur-based gases systematically investigated from a theoretical perspective. The results show that FeN4 embedded WNG can greatly enhance the adsorption ability and exhibits considerable sensitivity towards the H2S, SO2, SO3, SOF2 and SO2F2 gases due to the synergistic effect of N and Fe atoms. Meanwhile, FeN4-WNG sensor has good stability and can effectively detect sulfur-based gases in a humid environment. The electrical conductivity of FeN4-WNG system changed significantly after SO3 gas adsorption, which is conducive to the improvement of detection accuracy. FeN4-WNG is more suitable as a disposable gas sensor or gas scavenger for SO3 gas due to its strong adsorption capacity. In contrast, FeN4-WNG can be regarded as the excellent reusability sensor towards H2S, SO2 and SOF2 gases. Furthermore, applying positive and negative electric fields can further enhance the selectivity and sensitivity of H2S and SO3 gases. This work is meaningful to illuminate the gas-sensitive mechanism for experimentalists to realize the potential application of FeN4-WNG in the field of detecting and removing sulfur-based gases.