Novel high-performance H2Se sensor based on Zn/P-, Cd/P-, and Hg/P-modified graphitic carbon nitride sheets: A DFT study

The adsorption performance of hydrogen selenide (H2Se) on the Zn/P-, Cd/P-, and Hg/P-modified graphitic carbon nitride (gCN) was theoretically investigated. The results of calculations revealed that with adsorption of H2Se on the modified gCN materials, the electrical conductivity, magnetic moments, electron transfer, and optimized structures of these systems considerably modulated. The calculated adsorption energy of H2Se on the Zn/P-, Cd/P-, Hg/P-modified, and P-doped gCN materials was −1.502, −2.141, −2.917, and −0.378 eV, respectively. The obtained results displayed that with modification of gCN by Zn/P, Cd/P, and Hg/P elements, the adsorption abilities of gCN remarkably improved. Furthermore, it was found that with the adsorption of H2Se and also embedding of Zn, Cd, Hg, and P elements, the conductance of gCN materials significantly increased. This phenomenon is attributed to the created new impurity energy levels close to the Fermi level. In addition, the results of total magnetization displayed that with adsorption of H2Se over the Hg-modified gCN material, the magnetic moment of the system remarkably changed. Also, the results of electron density and Lowdin charges analysis revealed that the adsorption energy of H2Se over the Hg/P-modified gCN is higher than the other gCN materials. Therefore, it can be deduced that the Hg/P-modified gCN is a promising candidate for detecting and removing of H2Se from the atmosphere. On the other hand, it can be concluded that the Hg/P-modified gCN system with the highest adsorption energy can be effectively used for gas sensor application.