First‐principles investigation of electronic and optical properties of H‐doped FeS 2

Although the FeS2 is a promising electrocatalyst for hydrogen storage, the electronic and optical properties of the hydrogenated FeS2 are unclear. To solve these problems, we apply the first-principles calculations to study the hydrogenated behavior, electronic and optical properties of H-doped FeS2. The results show that the hydrogen is easy to store in cubic FeS2 compared to the orthorhombic FeS2. The reason is that the large interstice of cubic structure can enhance the interaction between H and FeS2. The narrow band gap of FeS2 improves the electronic transfer and enhances the catalytic activity. The hydrogenated FeS2 shows the strong electronic interaction between H and FeS2. The electronic structure shows that the hydrogenated FeS2 is attributed to the formation of H-S and H-Fe bonds. Finally, the adsorption spectrum affirms that the hydrogenated cubic FeS2 improves the electronic jump between the occupied state and the empty state.