Synergistic Engineering of Doping and Vacancy in Ni(OH)₂ to Boost Urea Electrooxidation

Advanced Functional Materials, Год журнала: 2022, Номер 33(4)

Опубликована: Ноя. 16, 2022

Abstract Nickel hydroxide (Ni(OH) 2 ) has been identified as one of the best promising electrocatalyst candidates for urea oxidation reaction (UOR) due to its flexible structures, wide compositions, and abundant 3d electrons under alkaline conditions. However, layered structure with limited exposed edge sites severely hinders further improvement UOR activity. Herein, oxygen‐vacancy rich vanadium doped Ni(OH) (O vac ‐V‐Ni(OH) catalysts are prepared synergistically boost electrooxidation. Vanadium doping contributes more active sites, simultaneously generates oxygen vacancies, switching rate‐determining step from *COOH deprotonation N–H bond cleavage process lowering thermodynamic barrier by around 1.13 eV. The novel O demonstrates good electrocatalytic performances a working potential 1.47 V at high current density 100 mA cm −2 . Synergistic engineering vacancy is strategy designing efficient electrocatalysts.

Язык: Английский

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Engineering Multilevel Collaborative Catalytic Interfaces with Multifunctional Iron Sites Enabling High-Performance Real Seawater Splitting

ACS Nano, Год журнала: 2023, Номер 17(2), С. 1681 - 1692

Опубликована: Янв. 3, 2023

Given the abundant reserves of seawater and scarcity freshwater, real electrolysis is a more economically appealing technology for hydrogen production relative to orthodox freshwater electrolysis. However, this greatly precluded by undesirable chlorine oxidation reaction severe chloride corrosion at anode, further restricting catalytic efficiency overall splitting. Herein, feasible strategy engineering multifunctional collaborative interfaces reported develop porous metal nitride/phosphide heterostructure arrays anchoring on conductive Ni2P surfaces with affluent iron sites. Collaborative among phosphide, bimetallic nitride, supports play positive role in improving water adsorption/dissociation adsorption behaviors active Fe sites evidenced theoretical calculations evolution reactions, enhancing oxygenated species nitrate-rich passivating layers resistant oxygen reaction, thus cooperatively propelling high-performance bifunctional The resultant material Fe2P/Ni1.5Co1.5N/Ni2P performs excellently as self-standing catalyst alkaline It requires extremely low cell voltages 1.624 1.742 V afford current densities 100 500 mA/cm2 1 M KOH electrolytes, respectively, along superior long-term stability, outperforming nearly all ever-reported non-noble electrocatalysts benchmark Pt/IrO2 coupled electrodes freshwater/seawater This work presents an effective catalysts toward green from

Язык: Английский

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Electrocatalytic seawater splitting: Nice designs, advanced strategies, challenges and perspectives

Materials Today, Год журнала: 2023, Номер 69, С. 193 - 235

Опубликована: Сен. 19, 2023

Язык: Английский

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Carbon Oxyanion Self‐Transformation on NiFe Oxalates Enables Long‐Term Ampere‐Level Current Density Seawater Oxidation

Angewandte Chemie International Edition, Год журнала: 2023, Номер 63(1)

Опубликована: Ноя. 23, 2023

Seawater electrolysis is an attractive way of making H2 in coastal areas, and NiFe-based materials are among the top options for alkaline seawater oxidation (ASO). However, ample Cl- can severely corrode catalytic sites lead to limited lifespans. Herein, we report that situ carbon oxyanion self-transformation (COST) from oxalate carbonate on a monolithic NiFe micropillar electrode allows safeguard high-valence metal reaction ASO. In situ/ex studies show spontaneous, timely, appropriate COST safeguards active against attack during ASO even at ampere-level current density (j). Our catalyst shows efficient stable performance, which requires overpotential as low 349 mV attain j 1 A cm-2 . Moreover, with protective surface CO32- exhibits slight activity degradation after 600 h under seawater. This work reports effective design concepts level self-transformation, acting momentous step toward defending seawater-to-H2 conversion systems.

Язык: Английский

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Ni₃N–CeO₂ Heterostructure Bifunctional Catalysts for Electrochemical Water Splitting

Advanced Functional Materials, Год журнала: 2023, Номер 33(47)

Опубликована: Сен. 3, 2023

Abstract Developing low‐cost and high‐efficient bifunctional catalysts for hydrogen evolution reaction (HER) oxygen (OER) is greatly significant water electrolysis. Here, Ni 3 N‐CeO 2 /NF heterostructure synthesized on the nickel foam, it exhibits excellent HER OER performance. As a result, electrolyzer based catalyst only needs 1.515 V@10 mA cm −2 , significantly better than that of Pt/C||IrO catalysts. In situ characterizations unveil CeO plays completely different roles in processes. infrared spectroscopy density functional theory calculations indicate introduction can optimizes structure interface water, synergistic effect N improve activity significantly, while Raman spectra reveal accelerates reconstruction O V (oxygen vacancy)‐rich NiOOH boosting OER. This study clearly unlocks catalytic mechanisms splitting, which provides useful guidance designing high‐performance splitting.

Язык: Английский

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Functional Bimetal Co‐Modification for Boosting Large‐Current‐Density Seawater Electrolysis by Inhibiting Adsorption of Chloride Ions

Advanced Energy Materials, Год журнала: 2023, Номер 13(32)

Опубликована: Июль 7, 2023

Abstract Designing efficient and durable electrocatalysts for seawater splitting to avoid undesired chlorine evolution reaction resist the corrosive is crucial electrolysis technology. Herein, a functional bimetal (Co Fe) designed specifically modify nickel phosphide (denoted as CoFe‐Ni 2 P) boosting splitting, where Fe atom improves conductivity of Ni P improving electron transfer, Co accelerates self‐reconstruction process favorably generate co‐incorporated NiOOH (CoFe‐NiOOH) species on electrode surface. Additionally, these in situ‐generated CoFe‐NiOOH remarkably inhibit adsorption Cl − ions but selectively adsorb OH ions, which contributes excellent performance large‐current‐density splitting. Therefore, only requires low overpotentials 266 304 mV afford current densities 100 500 mA cm −2 harsh 6 m KOH + electrolyte, can work stably 600 h. Impressively, flow‐type anion exchange membrane electrolyzer assembled by P/Ni‐felt bifunctional demonstrated run at an industrially large density 1.0 A electrolyte 350 h, shows promising application prospects.

Язык: Английский

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Boosting Oxygen Evolution Reaction of (Fe,Ni)OOH via Defect Engineering for Anion Exchange Membrane Water Electrolysis Under Industrial Conditions

Advanced Materials, Год журнала: 2023, Номер 35(44)

Опубликована: Авг. 22, 2023

Developing non-precious catalysts with long-term catalytic durability and structural stability under industrial conditions is the key to practical alkaline anion exchange membrane (AEM) water electrolysis. Here, an energy-saving approach proposed synthesize defect-rich iron nickel oxyhydroxide for efficiency toward oxygen evolution reaction. Benefiting from in situ cation exchange, nanosheet-nanoflake-structured catalyst homogeneously embedded in, tightly bonded to, its substrate, making it ultrastable at high current densities. Experimental theoretical calculation results reveal that introduction of Ni FeOOH reduces activation energy barrier reaction purposely created defects not only ensure exposure active sites maximize effective surface but also modulate local coordination environment chemisorption properties both Fe sites, thus lowering *O *OOH. Consequently, optimized d-(Fe,Ni)OOH exhibits outstanding activity laboratory conditions. The large-area d-(Fe,Ni)OOH||NiMoN pair requires 1.795 V reach a density 500 mA cm-2 absolute 12.5 A AEM electrolyzer overall electrolysis, showing great potential

Язык: Английский

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In Situ Regulating Cobalt/Iron Oxide‐Oxyhydroxide Exchange by Dynamic Iron Incorporation for Robust Oxygen Evolution at Large Current Density

Advanced Materials, Год журнала: 2023, Номер 36(5)

Опубликована: Сен. 25, 2023

Abstract The key dilemma for green hydrogen production via electrocatalytic water splitting is the high overpotential required anodic oxygen evolution reaction (OER). Co/Fe‐based materials show superior catalytic OER activity to noble metal‐based catalysts, but still lag far behind state‐of‐the‐art Ni/Fe‐based catalysts probably due undesirable side segregation of FeOOH with poor conductivity and unsatisfied structural durability under large current density. Here, a robust durable catalyst affording densities 500 1000 mA cm −2 at extremely low overpotentials 290 304 mV in base reported. This evolves from amorphous bimetallic FeOOH/Co(OH) 2 heterostructure microsheet arrays fabricated by facile mechanical stirring strategy. Especially, situ X‐ray photoelectron spectroscopy (XPS) Raman analysis decipher rapid reconstruction into dynamically stable Co 1‐x Fe x OOH active phase through iron incorporation CoOOH, which perform as real sites accelerating rate‐determining step supported density functional theory calculations. By coupling MoNi 4 /MoO cathode, self‐assembled alkaline electrolyzer can deliver cell voltage 1.613 V, better than commercial IrO (+) ||Pt/C (‐) most reported transition electrolyzers. work provides feasible strategy exploration design industrial water‐splitting large‐scale production.

Язык: Английский

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Hierarchical porous NiFe-P@NC as an efficient electrocatalyst for alkaline hydrogen production and seawater electrolysis at high current density

Inorganic Chemistry Frontiers, Год журнала: 2023, Номер 10(5), С. 1493 - 1500

Опубликована: Янв. 1, 2023

The TNiFe-P@NC presented excellent HER performance with an overpotential of 40 mV at 10 mA cm −2 and stability in KOH solution. An assembled NiFe-P@NC||NiFe-P@NC electrolyzer could drive 100/500 alkaline seawater electrolyte 1.77/1.93 V.

Язык: Английский

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Electronic modulation with Pt-incorporated NiFe layered double hydroxide for ultrastable overall water splitting at 1000 mA cm−2

Applied Catalysis B Environment and Energy, Год журнала: 2023, Номер 331, С. 122683 - 122683

Опубликована: Март 24, 2023

Язык: Английский

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