Although iron doping is widely reported to boost the oxygen evolution reaction (OER) activity of transition metal-based catalysts, its role in triggering in situ structural evolution remains poorly understood. Herein, we synthesize an Fe-doped CoSe catalyst and systematically elucidate its activation mechanism. Under OER conditions, Fe doping weakens the Co-Se bond and shifts the d-band center toward the Fermi level, thereby triggering the structural evolution of CoSe into highly active CoOOH and Co3O4. This process is accompanied by in situ Se leaching, and the sequential oxidation of Se species to selenate, together with the oxidation of Fe3+/Co3+ to higher valence states species. The reconstructed CoFeOOH@SeO42- lowers the energy barrier of the rate-determining *OH -> *O step. As a result, the CoFeSe delivers an overpotential of only 265 mV to achieve a current density of 10 mA cm-2 with a relatively low Tafel slope of 57.3 mV dec-1. Moreover, the anion exchange membrane water electrolyzer (AEMWE) assembled with CoFeSe/NF & Vert;NMF achieved a current density of 100 mA cm-2 at a voltage of 1.82 V, which is lower than that of RuO2 & Vert;NMF (1.98 V), highlighting its potential for practical implementation.

Integrating the hydrogen evolution reaction (HER) with the urea oxidation reaction (UOR) offers an effective approach toward energy-efficient hydrogen production. Nevertheless, designing cost-effective and high-performance bifunctional electrocatalysts that can efficiently catalyze both the HER and UOR remains a significant challenge. Herein, this work reports a cobalt phosphide (CoP) electrocatalyst with phosphorus vacancies. The introduction of phosphorus vacancies effectively redistributes the electronic structure of cobalt sites in CoP, accelerates interfacial charge transfer, and provides additional catalytically active sites, thereby significantly improving both HER and UOR performance. Electrochemical measurements reveal a clear correlation between vacancy density and catalytic activity, with higher phosphorus vacancy concentration leading to superior electrocatalytic behavior. For the UOR, CoP-VP20 achieves a current density of 100 mA cm-2 at a potential of 1.56 V. For the HER, CoP-VP20 delivers a current density of 100 mA cm-2 at a potential of -196 mV. This work provides valuable insights into defect-induced electronic modulation and offers a feasible pathway for the rational design of cost-effective, high-performance electrocatalysts for energy-efficient hydrogen production.

Uncontrolled dendrite growth and parasitic side reactions at defect‐rich regions severely limit the cycling stability of aqueous Zn‐ion batteries (AZIBs). Here, we propose a simple, carbon‐nanopatch strategy based on candle‐flame pyrolysis for stabilizing Zn anodes. After rinsing, the introduced carbon nanoparticles are mainly retained in microscopic defect‐rich regions, forming localized carbon nanopatches (CNPs) on the Zn surface. Experimental characterization and theoretical analysis suggest that these localized CNPs can help alleviate local electric‐field intensification, promote more uniform current‐density and interfacial Zn 2+ distribution, and reduce direct electrolyte exposure at defect‐rich regions. In addition, flame treatment may promote grain growth within the Zn foil, which can further improve interfacial stability. As a result, Zn@CNPs symmetric cells achieve cycling lifetimes of 3450 h at 1 mA cm −2 /1 mAh cm −2 and 3500 h at 5 mA cm −2 /1 mAh cm −2 . When paired with a β‐MnO 2 cathode, the full cell retains 74% of its capacity after 1000 cycles at 1 A g −1 , compared with 28% for the cell using Bare Zn. This work provides a simple and cost‐effective strategy for developing more stable aqueous Zn‐based batteries.

The hydrogen evolution reaction (HER) is fundamentally limited by the sluggish water dissociation step, while the oxygen evolution reaction (OER) is constrained by the reconstruction behavior of the catalyst under operating conditions. Herein, we report a Fe-doped NiMoOx nanoflower decorated with Fe-doped MoNi4 nanoparticles (Fe-MoNi4@NiMoOx). Density functional theory (DFT) calculations reveal that the incorporation of Fe lowers the Volmer step energy barrier for MoNi4, thereby boosting its HER performance. For the OER, Mo leaching drives the reconstruction of MoNi4 into catalytically active NiMoFeOOH@MoO42- . Furthermore, theoretical calculations confirm that Fe/Mo doping and adsorbed MoO42- facilitate rapid electron transfer within NiMoFeOOH and reduce the energy barrier of the rate-determining step for the OER. As a result, the Fe-MoNi4@NiMoOx catalyst delivers exceptional HER and OER activities, with overpotentials as low as 102 and 212 mV for HER, and 278 and 343 mV for OER at current densities of 100 and 500 mA cm- 2, respectively, alongside excellent stability exceeding 100 h at 500 mA cm- 2. When employed as both the cathode and anode in an anion exchange membrane water electrolyzer (AEMWE), this catalyst achieves current densities of 500 and 1000 mA cm- 2 at low cell voltages of 2.22 and 2.56 V, respectively, while maintaining stable operation for over 200 h at 500 mA cm- 2.

Constructing stable, molecularly defined active interfaces on cost-effective oxide supports is a pivotal yet unmet challenge in oxygen evolution reaction (OER) electrocatalysis, as conventional sacrificial or indirect strategies preclude direct control over the functional interface where catalysis unfolds. Herein, we demonstrate this concept on spinel iron oxide, achieving a robust Fe-(O,N)-C coordination shell on Fe3O4 via dual-ligand capture-reorganization. Density functional theory predictions of favorable electronic modulation from this dual-coordination are validated by operando spectroscopic and kinetic analyses. These reveal that the interface maintains dynamic stability under OER conditions, stabilizes high-valent iron-oxo species, and markedly enhances lattice oxygen participation, which provides fundamentally new insights into the self-adaptive reconstruction and operational stability of molecularly tailored interfaces. Remarkably, this purely molecular engineering enables Fe3O4 to overcome its sluggish reaction kinetics and inherent degradation tendency, achieving activity (eta 10 = 252 mV, 49 mV lower than pristine Fe3O4) and durability (only 0.17 mV h-1 decay over 300 h at 500 mA cm-2, one-fifteenth that of pristine Fe3O4 over 120 h) that also rival those of complex heterostructured systems reported. This work establishes a conceptual paradigm of direct molecular interfacial control for oxide electrocatalysts, offering a design rationale for developing high-performance materials for sustainable energy conversion.

A pivotal challenge for rechargeable zinc-air batteries (ZABs) lies in designing air electrocatalysts that enable simultaneous enhancement of oxygen reduction and evolution reaction (ORR/OER) kinetics because the inefficiency of either reaction directly limits both power-energy performance and cycling durability. Herein, we present a rationally designed bifunctional oxygen electrocatalyst derived from a self-assembled cobalt-based metal-organic framework-layered double hydroxide (Co-LDH-MOF) hybrid precursor, fabricated via a rapid and scalable ultrasonication-assisted aqueous route. The resulting material featured a compact core-shell architecture comprising curved, N-rich carbon layers for efficient ORR and abundant exposed CoOx sites for enhanced OER, while the strongly coupled metal-carbon interface facilitated electron transfer and reinforced electrochemical durability. Correspondingly, the catalyst exhibited exceptional bifunctional activity, reflected in a small potential gap (Delta E = Ej10 - E1/2) of 0.69 V, outperforming the ZIF-67-derived counterpart (0.85 V) and the noble-metal benchmark Pt/C-RuO2 (0.75 V). When assembled into a ZAB, it maintained a narrow charge-discharge voltage gap with minimal decay over 1000 h of charge-discharge cycling, ranking among the top-performing Co-based bifunctional catalysts reported. This work validates precursor-guided structural engineering as an effective strategy for the construction of electrocatalysts with dense and synergistic active sites for advanced energy applications.

Tetracycline hydrochloride (TCH) persisting in treated effluents endangers ecosystems and public health by interfering with biological functions and encouraging antibiotic resistance. To mitigate this problem, composites of BaTiO3 and ReS2 (BTRS) were prepared using a hydrothermal route and characterized by a suite of structural, optical, electrochemical, and piezoelectric techniques. Under simultaneous visible‑light illumination and ultrasonic vibration, the sample with intermediate ReS2 content (BTRS‑2) achieved a pseudo‑first‑order degradation constant of 0.02100 min−1, about 2.82 times larger than that recorded for bare BaTiO3 (0.00745 min−1). Enhanced performance is attributed to strong interfacial electric fields at the heterojunction that improve separation of photogenerated charges, favoring formation of superoxide radicals (•O2−) and photogenerated holes (h+), which dominate the oxidative pathway. The catalyst preserved 60% of its initial activity after four reuse cycles, showing acceptable stability and recyclability. These results suggest that ferroelectric–2D heterostructures like BTRS offer a promising strategy for piezo‑photocatalytic removal of antibiotic contaminants.

Layered double hydroxides (LDHs) are considered as one of highly promising alternatives to precious metal catalysts for oxygen evolution reaction (OER). However, the LDHs generally require prolonged prior activation for structural reconstruction, along with the inevitable dissolution and precipitation of active metal ions, thus weakening the stability. Herein, differently to the reported works, we report a universal strategy for direct activation of LDHs with simultaneous formation of protective and conductive TiN layers, to enable the efficient and durable water splitting at high current densities. It is verified that the plasma treatment shortens the length of Ni-O bond in NiO6 octahedron, which drives the structural distortion and triggers the phase evolution from NiFe-LDH to NiFeOOH. Consequently, the Ni 3d and O 2p center bands get closer to Fermi level with enhanced Ni-O covalency bonds, improving the adsorption energy and electron transfer over the OER process. Such developed NiFeOOH@TiN electrode without the often-required electrochemical prior activation delivers an ultralow overpotential of 288 mV to achieve current density of 100 mA cm(-2) for OER. Moreover, the anion exchange membrane water electrolysis assembled with NiFeOOH@TiN as both the anode and cathode exhibits a robust stability over 1100 h at a high current density of 1 A cm(-2), representing their promise for exploring efficient and durable bifunctional catalysts toward commercial applications.

The rational design of high-efficiency bifunctional oxygen electrocatalysts is fundamental to advancing rechargeable zinc-air batteries, yet it remains constrained by mismatched adsorption energies and sluggish kinetics of the oxygen reduction and evolution reactions (ORR/OER). Herein, a dual-ligand engineering strategy is reported to construct a hierarchical catalyst (CoFe-SA-NP@SNC) featuring atomically dispersed Co/Fe-N4 sites, integrated S-dopants, and confined CoFe alloy nanoparticles within an S,N-codoped carbon framework. A ZIF-mediated dual-template synthesis strategy facilitates the co-construction of multi-scale active centers within the carbon matrix, which form a locally coupled environment beneficial to accelerating oxygen redox kinetics. The optimized CoFe-SA-NP@SNC-700 catalyst exhibits a superior ORR half-wave potential of 0.87 V and a low OER overpotential of 319 mV at 10 mA cm-2, yielding a narrow bifunctional potential gap of 0.679 V. Furthermore, the integrated rechargeable Zn-air battery delivers a high peak power density of 179.3 mW cm-2 and an exceptional lifespan exceeding 400 h. Density functional theory calculations suggest that S dopants and coexisting alloy nanoparticles can jointly regulate the d-band center of Co/Fe-N4 moieties, optimizing the binding affinity of oxygen intermediates and lowering activation barriers for rate-determining steps. This work provides profound insights into coordination-environment engineering for high-performance energy conversion.

To achieve sustainable hydrogen production through seawater electrolysis, it is essential to develop efficient and stable electrocatalysts for the oxygen evolution reaction (OER). Herein, we develop a high-performance phosphate-modified nickel-iron catalyst directly on iron foam (FeNiPi/FF) via a facile and scalable two-step strategy, which integrates anodic electrodeposition and subsequent in situ soaking. Systematic structural characterization reveals that the optimized catalyst possesses a unique hierarchical nanoflower architecture, which confers a substantially increased electrochemical surface area. Furthermore, it is enriched with electrochemically active high-valence Ni3+/Fe3+ species and stabilized by strongly incorporated phosphate anions. This synergistic configuration enables the FeNiPi/FF electrode to demonstrate superior OER activity and robust durability in alkaline water and seawater. It requires low overpotentials of merely 320 and 346 mV to deliver a high current density of 500 mA cm- 2 in alkaline water and alkaline seawater electrolytes, respectively, and maintains superb long-term operational stability. This work not only provides a practical and effective pathway for designing non-precious metal catalysts with enhanced activity and corrosion resistance but also advances the development of efficient alkaline water and alkaline seawater splitting systems for a green hydrogen economy.

ABSTRACT The practical applications of aqueous zinc‐ion batteries (AZIBs) are hindered by Zn anode issues including dendrite growth, hydrogen evolution, passivation, and corrosion. To overcome these issues, surface modification stands out as an effective approach to enhance interfacial stability while retaining the intrinsic merits of Zn anodes. This review systematically summarizes recent advances in surface modification strategies for zinc anodes, focusing on mechanistic understanding, methodological innovations, and electrochemical performance. The key techniques, including protective coating deposition, functional interlayer construction, and in situ interface engineering, are critically examined to clarify their roles in regulating Zn 2+ flux, inhibiting side reactions, and improving electrochemical kinetics. Furthermore, the interaction between modified anode surfaces and electrolyte components is discussed to offer a comprehensive perspective on anode‐electrolyte synergy. Finally, we identify the persistent challenges related to the scalability, long‐term durability under practical conditions, and cost‐efficiency. We also propose future research directions, including the design of multifunctional hybrid coatings and the integration of machine learning‐assisted material screening, in conjunction with first‐principles calculations to predict the diffusion and deposition behavior of zinc ion at the electrode–electrolyte interface. This review aims to provide guidance for the rational design of durable zinc anodes, to facilitate the commercialization of AZIBs.

Efficient piezo-photocatalysis necessitates precise engineering of material morphology, interfacial charge dynamics, and film thickness. Guided by finite element analysis, which identified ultrathin fibrous layers as optimal for maximizing piezoelectric response, this study fabricated ZnO films with precisely tailored thickness via thermal atomic layer deposition. A SrTiO3/ZnO heterojunction was subsequently constructed to facilitate the separation and transport of photogenerated carriers. The introduction of the piezoelectric polarization field not only reinforced the heterojunction but also significantly accelerated surface reaction kinetics. Systematic comparison among photocatalysis, piezo-catalysis and piezo-photocatalysis unambiguously demonstrated a synergistic enhancement effect. Specifically, under visible light irradiation and with ultrasound excitation, the optimized STZ catalyst achieved 99.75% degradation of methyl orange within 60 min, outperforming most reported piezo-photocatalysts systems and validating our computation-guided design strategy. This work elucidates the underlying mechanisms of piezo-photocatalysis and provides a scalable framework for developing highperformance, environmentally friendly functional materials for wastewater treatment.

The design of efficient and cost-effective bifunctional catalysts to replace precious metal-based catalysts remains a critical challenge in electrocatalytic water splitting. Herein, we report a Mo-Fe co-doped Ni3S2 nanorod arrays grown on a nickel-iron foam substrate via a facile hydrothermal synthesis. This dual metal-doped nanorod structure synergistically modulates the electronic structure while maximizing accessible active sites, endowing the Mo-Fe-Ni3S2 electrode with exceptional bifunctional activity for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. The resulting Mo-Fe-Ni3S2 electrode requires only 180 mV for HER and 275 mV for OER at a current density of 100 mA cm(-2), coupled with long-term stability exceeding 50 h. Remarkably, when integrated into a single-stack cell for practical application, the Mo-Fe-Ni3S2 electrode exhibits outstanding performance, achieving a current density of 100 mA cm(-2) at a potential of 1.87 V and showing no potential degradation after 100 h of continuous operation at 100 mA cm(-2). This work not only presents a high-performance bifunctional catalyst but also provides fundamental insights into the design of advanced electrocatalysts through rational heteroatom doping strategies.

The development of efficient and stable catalysts for the oxygen evolution reaction (OER) is critical for the progress of electrocatalytic alkaline water and seawater hydrogen production. Herein, we report Se-vacancy-rich Fe-doped NiSe (VSe-FeNiSe/NFF) nanosheets with remarkable OER performance in both alkaline and seawater media. It is revealed that the Se vacancies significantly promote structural reconstruction during the OER process, which facilitates the formation of highly active NiFeOOH and SeO42- species, thus delivering exceptional catalytic activity and stability. Moreover, theoretical calculations reveal that introducing selenium vacancies upshifts the d-band center toward the Fermi level, facilitating electron excitation and interfacial charge transfer, while reducing the Gibbs free energy barrier of the rate-determining step. In alkaline media, they require an overpotential of 242 mV to achieve a current density of 100 mA cm-2, with a low Tafel slope of 30 mV dec-1 and robust stability over 500 h. Meanwhile, in seawater media, they just require an overpotential of 253 mV to achieve 100 mA cm-2, with a Tafel slope of 35.5 mV dec-1. Impressively, they could be operated stably for 100 h at 100 mA cm-2. This work not only elucidates the roles of Se vacancies in the reconstruction of selenides during the OER process, but also offers meaningful insight into exploring advanced electrocatalysts for the OER in both alkaline water and seawater media.

Developing crystalline-amorphous heterojunctions presents a promising pathway to enhance the electrocatalytic performance of both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). This study reports the exploration of novel crystalline-amorphous NixSy@NiFe LDH heterostructures for efficient HER and OER, which are synthesized via in situ growth of NiFe-LDH on nickel sulfide (NixSy) nanowires. The resultant three-dimensional core-shell structures remarkably increase the active sites, enhance the charge transfer, and facilitate the gas release during the catalytic process. In situ Raman spectroscopy and density functional theory (DFT) calculations verify that the introduced Fe could boost the OER activity by promoting the structural reconstruction to form the disorder of NiOOH@NiFeOOH species, and reducing the energy barrier for conversion of oxygen-containing intermediates. The heterojunction interface in NixSy@NiFe LDH modifies the electron distribution, thus significantly lowering the Gibbs free energy of hydrogen adsorption (Delta GH* = 0.1 eV) compared to that of NixSy. Correspondingly, the NixSy@NiFe LDH exhibits superior bifunctional performance for the HER and OER in alkaline solution, delivering high current densities of -100 and 200 mA cm-2 at low overpotentials of 159 and 250 mV for the HER and OER, respectively, as well as an excellent stability against operation over 250 h at 200 mA cm-2, implying its promise toward commercial applications.

The photoelectrochemical (PEC) water-splitting performance of TiO2-based photoanodes is highly dependent on their morphology. In this work, three distinct architectures-nanorods, nanotubes, and nanobranches-were synthesized through precise morphological manipulation. Comprehensive characterization using Field Emission Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD) and ultraviolet visible diffuse reflectance spectrometer (UV-Vis DRS) revealed their structural and optical properties, while PEC behavior was evaluated using chronoamperometry (current-time, I-t), linear sweep voltammetry (LSV), applied bias photon-to-current efficiency (ABPE), incident photon-to-current efficiency (IPCE), Mott-Schottky analysis, electrochemical impedance spectroscopy (EIS), and electrochemically active surface area (ECSA) measurements. TiO2 nanotubes (TO-NT), derived by etching TiO2 nanorods (TO-NR), exhibited enhanced PEC activity due to increased surface area. Notably, TiO2 nanobranches (TO-NB), featuring branched architectures and heterophase junctions, demonstrated the best performance. At 1.23 V vs. reversible hydrogen electrode (RHE), TO-NBs achieved the highest photocurrent density of 0.36 mA.cm-2, the lowest charge transfer resistance, and a maximum ABPE among the three samples. These results underscore the critical role of nano architectural design in optimizing interfacial charge dynamics and light-harvesting efficiency, making TO-NBs strong candidates for efficient PEC water splitting.

Nonprecious metal catalysts (NPMCs) for oxygen reduction reaction (ORR) in an alkaline environment provide a prominent advantage for the development of low-cost anion-exchange membrane fuel cells (AEMFCs). However, the synthesis of highly active NPMCs typically involves high-temperature pyrolysis, which increases the time consumption and energy input, especially during the scale-up process. Herein, we report the mild synthesis of a graphene aerogel-based pyrolysis-free NPMC (FePc-GA) for AEMFCs. The physical characterizations demonstrate a strong chemical coupling between the graphene aerogel and FePc in FePc-GA. The electrochemical evaluation evidences that this pyrolysis-free FePc-GA shows excellent ORR activity with a half-wave potential of 0.92 V in half-cell conditions. In addition, by regulation of the ink formulation, the AEMFC reaches a 16 times higher power density using this pyrolysis-free NPMC. This work highlights the feasibility of catalyst layer engineering that can significantly advance the application of cost-effective, sustainable catalysts for AEMFCs.

Elevating iron‐involved sites in NiFe (oxy)hydroxides significantly accelerates oxygen evolution reaction (OER) kinetics but often sacrifices stability due to extensive metal sites ablation during industrial electrolysis. Here, an ions migration‐induced stabilization strategy is introduced to explore robust NiFe (oxy)hydroxides catalysts for OER. The present approach involving cathodic polarization of Fe‐rich NiFe‐layered double hydroxides (LDH) facilitates selective substitution of Ni with Fe cations and deep substitution of oxyanions with OH ‐ , leading to decreased layer thickness, enriched Fe sites, and aggravated lattice distortion in reorganized NiFe‐LDH (R‐NiFe‐LDH). Correspondingly, R‐NiFe‐LDH fully transforms into γ‐(NiFe)OOH with retained nanosheet morphology, reduced distortions, and dramatically inhibited Fe dissolution during prolonged OER. It achieves exceptional durability at 500 mA cm −2 , retaining ≈90% Fe over 5 days, substantially outperforming pristine NiFe‐LDH (50% Fe loss). Over 2 months, R‐NiFe‐LDH delivers only a 70 mV overpotential increase, whereas NiFe‐LDH decays by 140 mV in just 75 h. An anion exchange membrane water electrolyzer applying R‐NiFe‐LDH as both electrodes exhibit zero decay at 1000 mA cm −2 for 100 h, compared to a decay rate of 3.6 mV h −1 for the NiFe‐LDH counterpart. This work showcases a straightforward approach for engineering atomic arrangements in metal (oxy)hydroxides catalysts toward robust water electrolysis.

Currently, the development of Fe/N/C catalysts is attracting more and more attention, due to their exciting potential applications in advanced anion-exchange membrane fuel cells (AEMFCs) and zinc-air batteries (ZABs). Among these, the main hurdle lies in the high mass transport resistance associated with the micropore-dominated Fe/N/C catalysts. In this work, we report the exploration of a carboxymethyl cellulose (CMC)-induced hierarchically porous hollow Fe/N/C aerogel (FeN-CA) catalyst, which remarkably enhances mass transport and improves the AEMFC/ZAB performance. It is witnessed that the resulting aerogel catalyst increases the mesoporous and macroporous structures, thus effectively reducing the oxygen transport resistance within the electrodes at high current densities. Consequently, the resulting FeN-CA catalyst in AEMFCs exhibits a reduced mass transfer overpotential (235 mV) at 1500 mA cm-2 and a peak power density of 774 mW cm-2 at 1724 mA cm-2, respectively. Moreover, in ZABs, it delivers an exceptional peak power density of up to 500 mW gcatalyst-1 (25 degrees C) and 766 mW gcatalyst-1 (80 degrees C), which is the highest among non-precious metal catalysts (NPMCs) ever reported, indicating their future potential in commercial applications.

The development of highly efficient and stable oxygen evolution reaction (OER) catalysts is crucial for advancing electrocatalytic alkaline hydrogen production. In this study, we present the development of a heterojunction nanosheet material, FeNiSx-NiSe2/NFF, composed of selenide and sulfide, which is synthesized through hydrothermal selenization followed by annealing for sulfidation. Structural characterization and electrochemical analysis confirm that both selenide and sulfide function as effective precatalysts, undergoing complete transformation into highly active FeNiOOH@NiOOH, with SO4 2-/SeO4 2- species adsorbed on the electrode surface. The optimized FeNiSx-NiSe2/NFF benefits from the enhanced heterointerfaces, which improve the interface charge distribution and facilitate the formation of FeNiOOH@NiOOH and SO4 2-/SeO4 2- active sites, thereby imparting exceptional activity and stability to the material. The FeNiSx-NiSe2/NFF catalyst requires an ultralow overpotential of only 239 mV to achieve a current density of 100 mA cm- 2, with a Tafel slope of 38.4 mV dec- 1, and maintains stable operation for over 100 h. This work not only successfully fabricates selenide and sulfide heterojunction pre-catalysts, but also elucidates the synergistic effects between selenide and sulfide heterojunctions in facilitating the transformation process and accelerating the formation of active species.