Seawater electrolysis is promising for green hydrogen production but suffers from chloride-induced anodic corrosion. Herein, a dual-anion synergistic protection strategy is proposed for durable alkaline seawater oxidation over V₂O₅ nanolayer coated NiFe layered double hydroxide nanosheets on Ni foam (V₂O₅@NiFe LDH/NF). During seawater oxidation process, the surface V₂O₅ component is reconstructed into adsorbed VO₄^3– species as an anion-enriched protective interface capable of electrostatically repelling Cl^– and mitigating chloride attack. In parallel, the interlayer CO₃^2– confined within NiFe LDH acts as an internal anionic barrier, suppressing Cl^– penetration into the LDH galleries and inhibiting its adsorption on catalytically active sites. The cooperative action of external VO₄^3– protection and internal CO₃^2– shielding endows V₂O₅@NiFe LDH/NF with robust catalytic activity and exceptional durability, delivering an overpotential of 370 mV at 1000 mA cm^–2 and maintaining stable operation for 1000 h under industrial-level current density. Furthermore, an anion-exchange membrane electrolyzer assembled with V₂O₅@NiFe LDH/NF as the anode and Pt/C/NF as the cathode requires only 2.02 V to achieve 500 mA cm^–2 and operates continuously for 1000 h. This study provides a rational dual-anion interfacial engineering strategy for developing durable electrodes under harsh chloride-containing environments.

Alkaline seawater electrolysis is promising for large-scale production of green hydrogen but the chlorine evolution reaction (CER) causes severe anode’s corrosion under high current densities. This work described the use of a sulfur-doped NiFe layered double hydroxide nanoarray on Ni foam (S-NiFe LDH/NF) synthesized through a two-step hydrothermal process as a durable catalyst for alkaline seawater oxidation. In 1 M KOH + seawater, the S-NiFe LDH/NF anode needs a low overpotential of 345 mV to afford a current density of 1000 mA·cm⁻² and operates stably over 800 h. Sulfate species generated on the catalyst surface, which is evidenced by in situ Raman spectroscopy analysis, electrostatically repel Cl⁻ and thus inhibits the CER. Furthermore, the two-electrode system using S-NiFe LDH/NF and Pt/C/NF as the anode and cathode, respectively, requires a cell voltage of 1.90 V to achieve a current density of 100 mA·cm⁻² and maintains stable operation for 1000 h at 500 mA·cm⁻² in alkaline seawater.

Alkaline seawater electrolysis for hydrogen production powered by clean energy is increasingly driving the development of a low-carbon economy. However, the limited proton availability in the electrolyte leads to sluggish cathodic reaction kinetics and elevates energy consumption, which hinders its large-scale application. Herein, low Pt loaded NiCo phosphate-coated NiCoP nanoneedle arrays on Ni foam (Pt@NCPi@NCP/NF) using a spontaneous redox strategy is developed for efficient and durable electrocatalytic hydrogen production from alkaline seawater. In situ Raman spectroscopy confirms that a large number of hydrated hydrogen ion intermediates are generated on the surface of Pt@NCPi@NCP/NF during the hydrogen evolution reaction (HER) process, which successfully constructs a localized acidic microenvironment. Concurrently, the surface Pi layer functions as a proton buffer layer, effectively regulating proton supply to enhance the utilization efficiency of active sites. As a result, the catalyst exhibits excellent HER kinetics under alkaline conditions with a Tafel slope of only 39.65 mV·dec^–1 and a low overpotential of 136 mV to reach 1000 mA·cm^–2.

Seawater electrolysis holds great promise for sustainable green hydrogen production, but it is challenged by chloride-induced corrosion. Herein, we demonstrate the hydrothermal preparation of Pb-doped NiFe layered double hydroxide on Ni foam (Pb-NiFe LDH/NF) for alkaline seawater oxidation electrocatalysis. Our Pb-NiFe LDH/NF requires a low overpotential of only 381 mV to attain a current density of 1000 mA·cm⁻², superior to its NiFe LDH/NF counterpart (423 mV). Additionally, it operates continuously for 1000 h with negligible performance degradation and minimal active chlorine production. In situ Raman spectroscopy analysis reveals that Pb incorporation facilitates catalyst surface reconstruction, thereby enhancing oxygen evolution reaction activity. Importantly, Pb selectively adsorbs free Cl⁻ to form stable Pb–Cl species under the influence of an applied electric field. This process creates a Cl⁻-free layer near the anode surface, thereby enhancing the catalyst’s chlorine corrosion resistance.

Water-soluble nitrite (NO₂⁻) in wastewater from agricultural and industrial activities poses ecological and health risks, and its electroreduction shows promise for ammonia (NH₃) production, but energy losses from the hydrogen evolution reaction (HER) limit its overall efficiency. In this work, we report the use of CoFe-layered double hydroxides on three-dimensional (3D) TiO₂ array (TiO₂@CoFe-LDH) as an effective electrocatalyst for NO₂⁻ reduction. By offering superior *H species supply and hydroprocessing capability, this catalyst achieves an NH₃ yield of 1056.4 μmol·h⁻¹·cm⁻² with a 97.4% Faradaic efficiency (FE) at −0.6 V and sustains FE above 87% across a range of applied potentials. Additionally, a 60-h simulated wastewater treatment experiment demonstrates its practical application potential.

H₂TiO₃ (HTO) emerges as a highly promising lithium-ion sieve (LIS) material for selectively and efficiently extracting lithium from liquid-phase systems. However, the practical use of conventional powdered HTO adsorbents is hindered by difficulties in recovery and titanium leaching, which limits their reusability. Herein, we design a novel HTO/MXene/polysulfone (HTO/MXene/PSF) hybrid membrane, where two-dimensional (2D) MXene nanosheets bridge PSF and HTO via enhanced hydrogen bonding and enable the in-situ self-assembly of HTO into spindle-like nanostructures. As anticipated, the hybrid membrane exhibits selective lithium adsorption, achieving a capacity of 25.80 mg·g⁻¹ from shale gas wastewater (SGW). Moreover, it maintains remarkable cyclic stability with a negligible decrease in adsorption capacity of merely 0.25% after ten consecutive adsorption–desorption cycles. Besides, filtration studies demonstrate that a membrane with a surface area of 12.56 cm² can effectively process 230 mL of SGW. Theoretical calculations reveal that hydrogen bonding and electronic interactions drive the self-assembly of HTO on MXene and further elucidate the adsorption strength and spatial hindrance mechanisms for selective lithium ion adsorption. This study introduces an innovative concept of in-situ self-assembled LIS in a hybrid membrane for lithium recovery from SGW, which is expected to inspire further research on self-assembled sieve-based adsorbents.

Fabricating catalysts with efficient water dissociation and robust stability is key to advancing the industrialization of the alkaline hydrogen evolution reaction (HER). Establishing an effective phosphide/oxide interface is a feasible way to improve the HER performance of the catalyst in an alkaline medium, but it remains challenging. Here, we adopt that manganese oxide nanoparticles decorated on nickel-cobalt phosphide nanowire array on nickel foam (MnO_x@NiCoP/NF) via a surface modification strategy that shifts the d-band center downward, promoting the water dissociation and hydrogen intermediate binding. Moreover, MnO_x makes the surface of NiCoP rougher, facilitating bubble release and improving the array stability. Consequently, MnO_x@NiCoP/NF achieves industrial current densities of 500 and 1000 mA·cm⁻² with overpotentials of 171 and 193 mV, respectively, while maintaining stable operation for over 600 h at 1000 mA·cm⁻² in 1 M KOH. Additionally, an anion exchange membrane electrolyzer with the catalyst was fabricated and shows potential for practical applications.

It is of great importance to design and develop electrocatalysts that are both long-lasting and efficient for seawater oxidation. Herein, a three-dimensional porous cauliflower-like Ni₃S₂ foam on Ni foam (Ni₃S₂ foam/NF) is proposed as a high-performance electrocatalyst for the oxygen evolution reaction in alkaline seawater. The as-synthesis Ni₃S₂ foam/NF achieves exceptional efficacy, achieving a current density of 100 mA·cm⁻² at mere overpotential of 369 mV. Notably, its electrocatalytic stability extends up to 1000 h at 500 mA·cm⁻².

Seawater electrolysis, especially in coastlines, is widely considered as a sustainable way of making clean and high-purity H₂ from renewable energy; however, the practical viability is challenged severely by the limited anode durability resulting from side reactions of chlorine species. Herein, we report an effective Cl⁻ blocking barrier of NiFe-layer double hydroxide (NiFe-LDH) to harmful chlorine chemistry during alkaline seawater oxidation (ASO), a pre-formed surface-derived NiFe-phosphate (Pi) outer-layer. Specifically, the PO₄³⁻-enriched outer-layer is capable of physically and electrostatically inhibiting Cl⁻ adsorption, which protects active Ni³⁺ sites during ASO. The NiFe-LDH with the NiFe-Pi outer-layer (NiFe-LDH@NiFe-Pi) exhibits higher current densities (j) and lower overpotentials to afford 1 A·cm⁻² (η₁₀₀₀ of 370 mV versus η₁₀₀₀ of 420 mV) than the NiFe-LDH in 1 M KOH + seawater. Notably, the NiFe-LDH@NiFe-Pi also demonstrates longer-term electrochemical durability than NiFe-LDH, attaining 100-h duration at the j of 1 A·cm⁻². Additionally, the importance of surface-derived PO₄³⁻-enriched outer-layer in protecting the active centers, γ-NiOOH, is explained by ex situ characterizations and in situ electrochemical spectroscopic studies.

Advancing efficient and affordable electrocatalysts to boost the oxygen evolution reaction (OER) is pivotal for sustainable green hydrogen production. Herein, we propose the fabrication of nickel-iron alloy nanoparticles-encapsulated on N-doped vertically aligned graphene array on carbon cloth (NiFe@NVG/CC) as a highly active three-dimensional (3D) catalyst electrode for OER. In 1 M KOH, such NiFe@NVG/CC demonstrates outstanding catalytic performance, necessitating merely overpotential of 245 mV for achieving a current density of 10 mA·cm⁻², a remarkably low Tafel slope of 36.2 mV·dec⁻¹. Furthermore, density functional theory calculations validate that the incorporate of N species into graphene can reinforce the electrocatalytic activity though reducing the reaction energy barrier during the conversion of *O to *OOH intermediates. The outstanding performance and structural benefits of NiFe@NVG/CC offer valuable insights for the development of innovative and efficient electrocatalysts for water oxidation.