A Thermodynamic Investigation of the Interaction of Ferric (Fe3+) Ion with (100, 110) Pyrite and (001) Chalcopyrite Surfaces Using the Density Functional Theory Study

As a heterogeneous catalyst, Pyrite increases chalcopyrite oxidation by creating more cathodic points and enhancing electron transfer to ferric (Fe3+) ions. In this study, the interaction of ferric ions with 100, 110 pyrite surfaces and 001-S, M (M= Cu and Fe) chalcopyrite surfaces was investigated using the Density functional theory (DFT) method and Material Studio software. The results showed that Fe3+ ion reacted well with the desired surfaces, and free energies were negative in the 25-275 °C temperature range, and interaction enthalpy increased linearly with increasing temperature. However, the two surfaces of 110 pyrite and 001-S chalcopyrite were more active than other surfaces, and a stronger reaction occurred between the ferric ion and that surfaces. Also, due to the strong metal-sulfur bond, the free energy of ferric ion interaction with the 001-M surface of chalcopyrite increased by increasing temperature. However, on the other surfaces, free energy was reduced in the presence of sulfur atoms.