It is an urgent requirement to develop non-precious metal-based catalysts with excellent electrocatalytic activity and stability to accelerate the development of hydrogen generation via energy-efficient routes. Herein, a facile and scalable strategy was developed to synthesize both rod-like Co(OH)F and Co–P nanoarrays supported on Ni-foam, denoted as Co(OH)F/NF and Co–P/NF, respectively. Electrochemical measurements demonstrate that Co–P/NF exhibits excellent electrocatalytic performance for the hydrogen evolution reaction (HER), delivering a low overpotential of 70 mV and 43 mV at 10 mA cm⁻² in alkaline and acid media, respectively. Furthermore, the as-prepared Co(OH)F/NF contributes to an outstanding oxygen evolution reaction (OER) performance with a low oxidation potential of about 1.5 V at 10 mA cm⁻². In addition, the Co(OH)F/NF also can enable highly efficient urea oxidation reaction (UOR) electrocatalysis, which can be utilized to substitute OER to lower the overpotential and thus reduce electrical energy consumption during H₂-production. As a proof of concept, full water-splitting measurements were performed with Co–P/NF and Co(OH)F/NF as cathode and anode, respectively, in 1 M KOH with 0.7 M urea. The Co–P/NF‖Co(OH)F/NF electrode is capable of producing a current density of 20 mA cm⁻² at a cell potential of only 1.42 V, which is 230 mV less than that for the urea-free counterpart, demonstrating its potential feasibility in practical applications of energy-efficient hydrogen production.

Oxygen vacancies‐enriched black TiO₂ is one promising support for enhancing hydrogen evolution reaction (HER). Herein, oxygen vacancies enriched black TiO₂ supported sub‐nanometer Pt clusters (Pt/TiO₂‐O_V) with metal support interactions is designed through solvent‐free microwave and following low‐temperature electroless approach for the first time. High‐temperature and strong reductants are not required and then can avoid the aggregation of decorated Pt species. Experimental and theoretical calculation verify that the created oxygen vacancies and Pt clusters exhibit synergistic effects for optimizing the reaction kinetics. Based on it, Pt/TiO₂‐O_V presents remarkable electrocatalytic performance with 18 mV to achieve 10 mA cm⁻² coupled with small Tafel slope of 12 mV dec⁻¹. This work provides quick synthetic strategy for preparing black titanium dioxide based nanomaterials.

Design of cost-effective bifunctional electrocatalysts for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is vital for developing hydrogen energy for the future. Herein, a cost-effective phosphorus-doped Co–Fe–B material with chain-like structure (denoted as Co₁–Fe₁–B–P) is reported as an efficient and novel bifunctional electrocatalyst for the OER and HER, and was produced via a facile water-bath synthesis and subsequent phosphorization. For the OER, the as-prepared Co₁–Fe₁–B–P nanochains require an extremely low overpotential of about 225 mV at 10 mA cm⁻² and possess a small Tafel slope of 40 mV dec⁻¹ in alkaline media. Impressively, the HER properties of Co₁–Fe₁–B–P nanochains are superior to those of P-free Co–Fe–B in terms of overpotential at 10 mA cm⁻² (173 mV vs. 239 mV) and kinetic Tafel slope (96 mV dec⁻¹vs. 105 mV dec⁻¹). The synergetic effect between Co–Fe–B and doped-P is mainly responsible for the satisfactory bifunctional performance, while the one-dimensional (1D) chain-like structure endows Co₁–Fe₁–B–P with abundant catalytically active sites that enhance the atom utilization efficiency. Moreover, the developed Co₁–Fe₁–B–P nanochains can be simultaneously utilized as both the cathode and anode for overall water-splitting, which requires a cell voltage of only 1.68 V to deliver 10 mA cm⁻². This work provides a feasible and promising protocol to realize metal borides as efficient electrocatalysts in energy-related applications.