We successfully report a liquid−liquid chemical reduction and hydrothermal synthesis of a highly stable columbite-tantalite electrocatalyst with remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in acidic media. The reduced Fe 0.79 Mn 0.21 Nb 0.16 Ta 0.84 O 6 (CTr) electrocatalyst shows a low overpotential of 84.23 mV at 10 mA cm −2 and 103.7 achieved at 20 mA cm −2 current density in situ for the HER and OER, respectively. The electrocatalyst also exhibited low Tafel slopes of 104.97 mV/dec for the HER and 57.67 mV/ dec for the OER, verifying their rapid catalytic kinetics. The electrolyzer maintained a cell voltage of 1.5 V and potential−time stability close to that of Pt/C and RuO 2 . Complementary first-principles density functional theory calculations identify the Mn sites as most active sites on the Fe 0.75 Mn 0.25 Ta 1.875 Nb 0.125 O 6 (100) surface, predicting a moderate Gibbs free energy of hydrogen adsorption (ΔG H* ≈ 0.08 eV) and a low overpotential of η = 0.47 V. The |ΔGMn H *| = 0.08 eV on the Fe 0.75 Mn 0.25 Ta 1.875 Nb 0.125 O 6 (100) surface is similar to that of the wellknown and highly efficient Pt catalyst (|ΔGPt H *| ≈ 0.09 eV).

Single‐atomic catalysts based on ruthenium have a balanced efficiency for water splitting, but it is necessary to control their activity and durability. In this work, a binder‐free Fe2‐xRuxNb2O6 (FRNO) hybrid catalyst is rationally designed through a facile hydrogel‐crosslinking route. The as‐prepared FRNO catalyst exhibits high electrocatalytic activity and stability when operating under acidic (0.5 m H2SO4) and alkaline (1 m KOH) media. Operando X‐ray adsorption and density functional theory calculations show that FRNO/CC, with its high intrinsic conductivity, promotes the adsorption and dissociation of water on its surface by regulating the charge distribution via charge transfer to the coordinated surface oxygen. This facilitates the oxygen evolution reaction (OER) performance by stabilizing *OOH adsorption on Ru and Fe. The FRNO/carbon cloth (CC) hybrid catalyst also delivers excellent activity and stability for both hydrogen evolution reaction (HER) and OER in pH‐universal electrolytes with low overpotentials of 30 mV per 82 mV for HER and 200 mV per 260 mV for OER at a current density of 10 mA cm‐2 in acidic/basic medium. Ultimately, the FRNO/CC hybrid catalyst shows good water‐splitting performance, and it is expected to help contribute to the creation of various hybrid electrocatalysts.

Herein, a simple synthetic approach is employed for the atomic dispersion of Rh atoms (Rh SAs) over the surface of interconnected Mo2C nanosheets intimately embedded in a three‐dimensional NixMoOy nanorod arrays (NixMoOy NRs) framework; we found that the introduction of both isolated Rh SAs and NixMoOy NRs adjusts the electrocatalytic function of the host Mo2C toward the direction of being an advanced and highly stable electrocatalyst for efficient hydrogen evolution at pH‐universal conditions. As a result, the proposed catalyst outperforms most recently reported transition metal‐based catalysts, and its performance even rivals that of commercial Pt/C, as demonstrated by its ultralow overpotentials of 31.7, 109.7, and 95.4 mV at a current density of 10 mA cm−2, along with its small Tafel slopes of 42.4, 51.2, and 46.8 mV dec−1 in acidic, neutral, and alkaline conditions, respectively. In addition, the catalyst shows remarkable long‐term stability over all pH values with good maintenance of its catalytic activity and structural characteristics after continuous operation.