Modulating Built‐In Electric Field Via N‐Doped Carbon Dots for Robust Oxygen Evolution at Large Current Density

Small, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 16, 2025

Constructing a built-in electric field (BIEF) within heterostructures has emerged as compelling strategy for advancing electrocatalytic oxygen evolution reaction (OER) performance. Herein, the p-n type nanosheet array heterojunction Ni2P-NCDs-Co(OH)2-NF are successfully prepared. The variation in interaction affinity between nitrogen N-doped carbon dots (NCDs) and Ni/Co induces charge redistribution Co Ni Ni2P-NCDs-Co(OH)2-NF-3 heterostructure, thereby enhancing intensity of BIEF, facilitating electron transfer, markedly improving OER activity. optimized electrocatalyst, Ni2P-NCDs-Co(OH)2-NF-3, demonstrates remarkably low overpotential 389 mV at 500 mA cm-2, alongsides small Tafel slope 65 dec-1, expansive electrochemical active surface area (ECSA), impedance, outstanding stability exceeding 425 h Faradaic efficiency up to 96%. In situ Raman spectroscopy density functional theoretical (DFT) calculations elucidate mechanism, revealing that enhanced BIEF optimizes adsorption energy Co3+ OH- weakened desorption during reaction. work ponieeringly employed NCDs regulator effectively tuning achieving superior performance under large current density, thus charting new pathways development high-efficiency electrocatalysts.

Language: Английский

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Tunable NiSe‐Ni₃Se₂ Heterojunction for Energy‐Efficient Hydrogen Production by Coupling Urea Degradation

Small Methods, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 7, 2025

Abstract Urea‐assisted water splitting is a promising energy‐saving hydrogen (H 2 ) production technology. However, its practical application hindered by the lack of high‐performance bifunctional catalysts for urea oxidation reaction (UOR) and evolution (HER). Herein, heterostructured catalyst comprising highly active NiSe Ni 3 Se , along with conductive graphene‐coated nickel foam skeleton (NiSe‐Ni /GNF) reported. The NiSe‐Ni originates from in situ selenization foam, allowing careful regulation to ratio simply adjusting calcination temperature. Theoretical calculations charge transfer between components can optimize pathways reduce corresponding energy barriers. Accordingly, designed exhibits excellent UOR HER activity stability. Furthermore, /GNF‐based UOR‐HER electrolyzer requires only 1.54 V achieve current density 50 mA cm −2 which lower than many recent reports much 1.83 OER‐HER electrolyzers. Moreover, exhibited negligible cell voltage variation during 28‐h stability test, indicating satisfactory stability, provides new viable paradigm H production.

Language: Английский

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Dual‐Functional Ca‐Ion‐Doped Layered δ‐MnO₂ Cathode for High‐Performance Aqueous Zinc‐Ion Batteries

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 3, 2024

Abstract Aqueous zinc‐ion batteries (ZIBs) have gained significant attention owing to their high energy densities, low costs, and enhanced safety profiles. However, the development of suitable host materials (i.e., cathodes) with capacity, structural stability, rate performance remains challenging. Herein, a nanoflower‐like Ca 0.10 MnO 2 ·0.61H O (CaMnO) is successfully synthesized as high‐performance cathode material for ZIBs using simplified one‐step hydrothermal method. The unique 3D porous structure provides continuous conductive path abundant adsorption sites Zn 2+ ions mitigates aggregation during long‐term cycling processes. In addition, doping into interlayer has dual functional effect: 1) it acts pillar broaden spacing enhance crystal 2) induces formation oxygen vacancies reaction kinetics increase reversible capacity. Therefore, CaMnO exhibits specific capacity 289 mAh g −1 , excellent retention (90%) over 750 cycles at current 1.5 A . This study new perspective on advanced ZIBs.

Language: Английский

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Ni_xB/Mo_0.8B₃ Nanorods Encapsulated by a Boron‐Rich Amorphous Layer for Universal pH Water Splitting at the Ampere Level

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 4, 2024

Abstract Heterostructured interfaces are crucial to electrocatalysts for water splitting. Herein, coral‐like multiheterostructured Ni x B/Mo 0.8 B 3 (NMB) nanorods encapsulated by a boron‐rich amorphous layer prepared Density‐functional theory (DFT) calculations indicate that the NMB interface adjusts d ‐band center and electronic structure of molybdenum sites. Owing strong coupling between Ni, Mo, at heterojunction, large number exposed catalytic active sites, as well special hydrophilic characteristics endowed surrounding layer, catalyst exhibits remarkable universal‐pH hydrogen evolution reaction (HER) activity with low overpotentials ( η ) 15, 26, 83 mV deliver 10 mA cm −2 in basic, acid, neutral media, respectively, outstanding oxygen (OER) basic medium 500 170 420 mV, respectively. The unique self‐supporting 3D hierarchical interconnected facilitates mass transport thus leading high mechanical stability 450 200 h HER OER ≈1000 . More importantly, excellent performance toward overall‐water electrolysis bifunctional ultralow cell voltages 1.45/1.56/1.85 V @ 10/100/1000 , demonstrating potential industrial splitting applications.

Language: Английский

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Construction of superhydrophilic FeP–Ni₂P–CoP/NF enriched interfacial heterostructures for promoting efficient and stable overall water splitting under large currents

Inorganic Chemistry Frontiers, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

It is of great importance to devise highly effective and durable non-precious metal catalysts capable operating at high current densities, in order cater the requirements practical applications.

Language: Английский

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Chromium‐Doped NiBP Micro‐Sphere Electrocatalysts for Green Hydrogen Production under Industrial Operational Conditions

Small Methods, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 19, 2025

Abstract Wide spread adaptation of green hydrogen can help to mitigate the serious climate issues, increasing global energy demands and development advanced electrocatalysts robust under industrial conditions is one key technological challenges. Herein, chromium‐doped nickel‐boride‐phosphide (Cr/NiBP) micro sphere (MS) electrocatalyst demonstrated via a two‐step hydrothermal approach along with post‐annealing. The Cr/NiBP MS demonstrates low evolution reaction oxygen evaluation over potentials 78 250 mV at 100 mA cm −2 in 1 m KOH, out performing most reported catalysts. ǁ exhibits only 1.54 V KOH surpasses benchmark RuO 2 (+) Pt/C (−) up 2000 , which sets it as best bifunctional electrocatalysts. Impressively, maintains stable performance for 240 h 1000 6 60°C, demonstrating rapid response, anti‐corrosion resistance, structural integrity meet operational conditions. Further, super‐low cell‐voltage 2.25 . small amount Cr atoms incorporation significantly enhance active sites intrinsic properties, accelerating water dissociation intermediate formation.

Language: Английский

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Effective hydrogen evolution enabled by heterogeneous interface engineering in bimetallic sulfide with MoNi alloy

Rare Metals, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 11, 2025

Language: Английский

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In situ Construction of Free-Standing High-Performance Ni-Based Dual Intermetallic Composites for Alkaline Hydrogen Evolution

Transactions of Tianjin University, Journal Year: 2025, Volume and Issue: unknown

Published: March 10, 2025

Language: Английский

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Dynamic Reconstruction of Ce‐Doped Fe₂P/NiCoP Hybrid for Ampere‐Level Oxygen Evolution in Anion Exchange Membrane Water Electrolysis

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: March 10, 2025

Abstract The sluggish kinetics of the oxygen evolution reaction (OER) critically limit efficiency anion exchange membrane water electrolysis (AEMWE). Herein, a Ce‐doped bimetallic Fe 2 P/NiCoP hybrid pre‐catalyst that undergoes dynamic reconstruction to activate highly efficient OER pathway is designed. optimized Ce 0.1 ‐Fe exhibits an impressively low overpotential 280 mV at 0.5 A cm −2 and small Tafel slope 55.3 dec −1 in 1.0 M KOH. Remarkably, when integrated as anode AEMWE electrolyzer, it delivers cell voltage 1.812 V maintains stable performance for over 500 h 60 °C. In situ characterizations density functional theory (DFT) calculations reveal Ce‐doping enhances surface modulates electronic structure, thereby reducing energy barriers intermediates (Δ G *OH Δ *OOH ) formation accelerating kinetics. This work introduces novel strategy utilize catalyst reconstruction, advancing their applications systems.

Language: Английский

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Tuning D‐Band Center of Vanadium in Constructing Lattice‐Matched Coherent Heterostructure for Enhanced Sodium Storage

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: March 10, 2025

Abstract A multiphasic K 0.147 Na 4.853 V 12 O 32 /NaV 6 15 @C (KNVO/NVO@C) heterostructure is realized to feature a lattice‐matched coherent interface with strong interfacial electric field in the cathodes, thereby elevating d‐band center and strengthening adsorption transportation of + enhanced capacity. The heterostructured KNVO/NVO@C cathode exhibits an exceptional rate capability (235.2 mAh g −1 at 0.2 C 151.7 10 C) ultralong cycling stability high capacity retention 95% after 1000 cycles 5 C. It found that synergy between structural properties stress generated by work function difference heterointerface upshifts vanadium toward Fermi level, which effectively lowers diffusion barrier, facilitates charge transfer, accelerates reaction kinetics electron/ion transport. calculated coefficient reaches ≈10 −11 cm 2 s , highly exceeding KNVO electrode. These findings offered robust framework for rational engineering develop next‐generation high‐performance energy storage devices.

Language: Английский

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