Effect of FeCo2S4 on electrocatalytic I3− reduction: Theoretical and experimental aspects

Abstract The design and preparation of alternative noble metal catalysts play a crucial role in energy conversion and storage fields. Herein, FeCo2S4 was designed and synthesized for electrocatalytic reduction from I3− to I− and the mirror-like FeCo2S4 displayed excellent chemical, thermal and mechanical stability. The adsorption energy of I3− ions adsorbed on the surface of (3 1 1), (4 2 2) and (4 4 0) were calculated by the density functional theory calculation, referring to the Fe, Co and S sites. The simulation results showed that the (3 1 1), (4 2 2) and (4 4 0) surfaces all exhibit higher adsorption capacity than that of Pt, resulting in higher catalytic activity. Dye-sensitized solar cell based on optimized FeCo2S4 showed high photoelectric conversion efficiency (7.4%) compared to Pt (6.8%), FeS (4.1%) and CoS (6.2%) under the simulated illumination (AM 1.5G, 100 mW cm−2).