FeSe₂/TiO₂ heterostructure as an efficient photocatalyst and their electrochemical energy storage applications

This paper reported the facile synthesis of FeSe₂ and TiO₂ and their different wt.% composites (75 and 50% of TiO₂, here after FT-1 and FT-2) via solvothermal in/ex-situ sol-gel method for the first time efficient photocatalytic degradation of Rhodamine removal and supercapacitor applications. Small bandgap energy was obtained for FT-1 samples from the optical analysis, with a more negligible band edge absorption. The result shows that the composite of FeSe₂ and TiO₂ increases the absorption, which collectively enhances the separation of the charge carriers and redox activities. The photocatalytic activities analysis demonstrated that the FT-1 sample reveals the fastest removal of the RB dye in just 60 min (FT-2, FeSe₂, and TiO₂ = 90, 100, and 180 min) with good stability (98%) after several cycles. As supercapacitor electrode materials, all electrodes showed well-defined peaks in their CV loops and voltage plateaus in their charge/discharge profile, illustrating the pseudocapacitive charge storage mechanism. No voltage decay was observed during many discharge currents from the charge/discharge investigation, demonstrating the chosen potential frame is a suitable window for the FeSe₂ and TiO₂ nanomaterials. The higher capacity of 295 (FT-1) than other electrodes (FeSe₂, TiO₂, and FT-2 = 220, 115, and 240 C/g) at 1 A/g was obtained to reach 180 at 10 A/g, resulting in an enhanced rate capability of 82%. The high rate capability is the cause of its more minor charge transfer resistance, resulting in higher conductivity and supporting rapid charge transport kinetics. These outstanding properties open a new avenue for other FeSe₂ and TiO₂ nanomaterials for efficient energy storage technologies.