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

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 I-3(-) to I and the mirror-like FeCo2S4 displayed excellent chemical, thermal and mechanical stability. The adsorption energy of I-3(-) ions adsorbed on the surface of (311), (422) and (440) were calculated by the density functional theory calculation, referring to the Fe, Co and S sites. The simulation results showed that the (311), (422) and (440) surfaces all exhibit higher adsorption capacity than that of Pt, resulting in higher catalytic activity. Dyesensitized 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).