Regulate electric double layer for one-step synthesize and modulate the morphology of (oxy)hydroxides

FeOOH have received considerable attention due to their natural abundance and cost-effectiveness. Despite the significant progress achieved, the one-step synthesis of integrated FeOOH is still a major challenge. Meanwhile, the current research on FeOOH catalyst still suffers from the unclear mechanism of controlling morphology. Here, density functional theory (DFT) calculations and X-ray photoelectron spectroscopy (XPS) demonstrated the strong electron-capturing and hydrogen absorption ability of Co in FeOOH, which further promotes the formation and stabilization of FeOOH. We used a one-step electrodeposition method to synthesize Co introduced FeOOH integrated electrocatalyst and propose to introduce ions with different valence states to regulate the morphology of FeOOH by precise modulation of electric double layer (EDL) composition and thickness. The prepared Co-FeOOH-K⁺ has a larger electrochemically active surface area (ECSA) (325 cm²) and turnover frequency (TOF) value (0.75 s⁻¹). In the electrochemical experiments of an alkaline anion exchange membrane electrolyzer, Co-FeOOH-K⁺ shows better oxygen evolution performance than commercial RuO₂ under industrial production conditions and has good industrial application prospects.