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

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.