Regulating electronic states of nitride/hydroxide to accelerate kinetics for oxygen evolution at large current density

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: April 4, 2023

Rational design efficient transition metal-based electrocatalysts for oxygen evolution reaction (OER) is critical water splitting. However, industrial water-alkali electrolysis requires large current densities at low overpotentials, always limited by intrinsic activity. Herein, we report hierarchical bimetal nitride/hydroxide (NiMoN/NiFe LDH) array as model catalyst, regulating the electronic states and tracking relationship of structure-activity. As-activated NiMoN/NiFe LDH exhibits industrially required density 1000 mA cm-2 overpotential 266 mV with 250 h stability OER. Especially, in-situ electrochemical spectroscopic reveals that heterointerface facilitates dynamic structure to optimize structure. Operando impedance spectroscopy implies accelerated OER kinetics intermediate due fast charge transport. The mechanism revealed combination theoretical experimental studies, indicating as-activated follows lattice oxidation kinetics. This work paves an avenue develop catalysts via tuning states.

Language: Английский

---

Fundamental Understanding of Structural Reconstruction Behaviors in Oxygen Evolution Reaction Electrocatalysts

Advanced Energy Materials, Journal Year: 2023, Volume and Issue: 13(31)

Published: June 29, 2023

Abstract Transition metal‐based oxyhydroxides (MOOH) derived from the irreversible structural reconstruction of precatalysts are often acknowledged as real catalytic species for oxygen evolution reaction (OER). Typically, reconstruction‐derived MOOH would exhibit superior OER activity compared to their directly synthesized counterparts, despite being fundamentally similar in chemistry. As such, has emerged a promising strategy boost electrocatalysts. However, in‐depth understanding origin reconstructed materials still remains ambiguous, which significantly hinders further developments highly efficient electrocatalysts based on In this review, comprehensive overview behaviors reported is provided and intrinsic chemical origins high efficiency toward unveiled. The fundamentals mechanisms, along with recommended characterization techniques dynamic process analyzing structure also interpreted. Finally, view chemistry, potential perspectives facilitate design synthesis durable electrocatalyst presented.

Language: Английский

---

Doped Mn Enhanced NiS Electrooxidation Performance of HMF into FDCA at Industrial‐Level Current Density

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(24)

Published: March 13, 2023

Abstract Electrooxidation of 5‐hydroxymethylfurfural (HMF) into 2,5‐furandicarboxylic acid (FDCA) is a highly promising approach for producing value‐added chemicals from biomass. However, developing efficient electrocatalysts HMF oxidation (HMFOR) with high current density in large‐scale productions remains challenge. Herein, it demonstrated that the Mn‐doped NiS nanosheet grown directly on 3D graphite felt (GF) substrates can efficiently perform electrooxidation FDCA at industrial‐level (500 mA cm −2 ) H‐cell. The Mn 0.2 NiS/GF exhibits excellent HMFOR performance selectivity (98.3%), yield (97.6%), faradaic efficiency (94.2%), and robust stability (10 cycles). Especially, production rate up to 4.56 g h −1 be achieved, superior those reported literatures. Furthermore, by scaling electrode area assembling continuous‐flow electrolyzer, 44.32 achieved. activity attributed incorporation material, theoretical calculation results indicate Ni as both adsorption sites oxidation, thereby effectively facilitate electro‐oxidation performance. This work provides strategy potential industrial‐grade large density.

Language: Английский

---

Flexible Zinc–Air Batteries with Ampere‐Hour Capacities and Wide‐Temperature Adaptabilities

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(13)

Published: Jan. 30, 2023

Flexible Zn-air batteries (FZABs) have significant potentials as efficient energy storage devices for wearable electronics because of their safeties and high energy-to-cost ratios. However, application is limited by short cycle lives, low discharge capacities per cycle, charge/discharge polarizations. Accordingly, herein, a poly(sodium acrylate)-polyvinyl alcohol (PANa-PVA)-ionic liquid (IL) hydrogel (PANa-PVA-IL) prepared using hygroscopic IL, 1-ethyl-3-methylimidazolium chloride, an additive twin-chain PANa-PVA. PANa-PVA-IL exhibits conductivity 306.9 mS cm-1 water uptake 2515 wt% at room temperature. Moreover, low-cost bifunctional catalyst, namely, Co9 S8 nanoparticles anchored on N- S-co-doped activated carbon black pearls 2000 (Co9 -NSABP), synthesized, which demonstrates O2 reversibility potential gap 0.629 V. FZABs based -NSABP demonstrate 1.67 mAh cm-2 long lives 330 h. Large-scale flexible rechargeable pouch cells exhibit total 1.03 Ah densities 246 Wh kgcell-1 . This study provides new information about hydrogels with ionic conductivities uptakes should facilitate the in electronics.

Language: Английский

---

Defect Engineered Metal–Organic Framework with Accelerated Structural Transformation for Efficient Oxygen Evolution Reaction

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(43)

Published: Sept. 6, 2023

Metal-organic frameworks (MOFs) have been increasingly applied in oxygen evolution reaction (OER), and the surface of MOFs usually undergoes structural transformation to form metal oxyhydroxides serve as catalytically active sites. However, controllable regulation reconstruction process remains a great challenge. Here we report defect engineering strategy facilitate during OER with enhanced activity. Defective (denoted NiFc'x Fc1-x ) abundant unsaturated sites are constructed by mixing ligands 1,1'-ferrocene dicarboxylic acid (Fc') defective ferrocene carboxylic (Fc). series more prone be transformed compared non-defective (NiFc'). Moreover, as-formed derived from contain vacancies. NiFc'Fc grown on nickel foam exhibits excellent catalytic activity an overpotential 213 mV at current density 100 mA cm-2 , superior that undefective NiFc'. Experimental results theoretical calculations suggest vacancies adsorption oxygen-containing intermediates centers, thus significantly improving

Language: Английский

---

A Review of Transition Metal Boride, Carbide, Pnictide, and Chalcogenide Water Oxidation Electrocatalysts

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(23), P. 12795 - 13208

Published: Nov. 15, 2023

Transition metal borides, carbides, pnictides, and chalcogenides (X-ides) have emerged as a class of materials for the oxygen evolution reaction (OER). Because their high earth abundance, electrical conductivity, OER performance, these electrocatalysts potential to enable practical application green energy conversion storage. Under potentials, X-ide demonstrate various degrees oxidation resistance due differences in chemical composition, crystal structure, morphology. Depending on oxidation, catalysts will fall into one three post-OER electrocatalyst categories: fully oxidized oxide/(oxy)hydroxide material, partially core@shell unoxidized material. In past ten years (from 2013 2022), over 890 peer-reviewed research papers focused electrocatalysts. Previous review provided limited conclusions omitted significance "catalytically active sites/species/phases" this review, comprehensive summary (i) experimental parameters (e.g., substrates, loading amounts, geometric overpotentials, Tafel slopes, etc.) (ii) electrochemical stability tests post-analyses publications from 2022 is provided. Both mono polyanion X-ides are discussed classified with respect material transformation during OER. Special analytical techniques employed study reconstruction also evaluated. Additionally, future challenges questions yet be answered each section. This aims provide researchers toolkit approach showcase necessary avenues investigation.

Language: Английский

---

Optimization of oxygen evolution activity by tuning e*g band broadening in nickel oxyhydroxide

Energy & Environmental Science, Journal Year: 2023, Volume and Issue: 16(2), P. 641 - 652

Published: Jan. 1, 2023

In Ni(OH) 2 , a greater extent of band (3d electron states with e g symmetry) broadening can facilitate transfer from the electrocatalyst to external circuit, leading higher OER catalytic performance.

Language: Английский

---

Unraveling the Synergistic Mechanism of Bi‐Functional Nickel–Iron Phosphides Catalysts for Overall Water Splitting

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(33)

Published: April 27, 2023

Abstract Ni–Fe bimetallic electrocatalysts are expected to replace existing precious metal catalysts for water splitting and achieve industrial applications due their high intrinsic activity low cost. However, the mechanism by which Ni Fe species synergistically enhance catalytic remains obscure, still needs further in‐depth study. In this study, a highly active bi‐functional electrocatalyst of 2 P/FeP heterostructures is constructed on foam (Ni P/FeP‐FF), clearly illustrating effect oxygen evolution reaction (OER) revealing true phase hydrogen (HER). The P/FeP‐FF only overpotentials 217 42 mV reach 10 mA cm −2 OER HER, respectively, exhibiting superior overall splitting. can elevate strength FeO surface promote formation high‐valence FeOOH during OER, thus enhancing performance. Based first‐principles calculations Raman characterizations, P/Ni(OH) heterojunction evolved from identified as real HER. This study not builds near‐commercial bifunctional splitting, but also provides deep insight synergistic species.

Language: Английский

---

Molecular Engineering of Metal–Organic Frameworks as Efficient Electrochemical Catalysts for Water Oxidation

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(22)

Published: March 13, 2023

Metal-organic framework (MOF) solids with their variable functionalities are relevant for energy conversion technologies. However, the development of electroactive and stable MOFs electrocatalysis still faces challenges. Here, a molecularly engineered MOF system featuring 2D coordination network based on mercaptan-metal links (e.g., nickel, as Ni(DMBD)-MOF) is designed. The crystal structure solved from microcrystals by continuous-rotation electron diffraction (cRED) technique. Computational results indicate metallic electronic Ni(DMBD)-MOF due to Ni-S coordination, highlighting effective design thiol ligand enhancing electroconductivity. Additionally, both experimental theoretical studies that (DMBD)-MOF offers advantages in electrocatalytic oxygen evolution reaction (OER) over non-thiol 1,4-benzene dicarboxylic acid) analog (BDC)-MOF, because it poses fewer barriers during rate-limiting *O intermediate formation step. Iron-substituted NiFe(DMBD)-MOF achieves current density 100 mA cm-2 at small overpotential 280 mV, indicating new platform efficient OER catalysis.

Language: Английский

---

Lewis Acid Driving Asymmetric Interfacial Electron Distribution to Stabilize Active Species for Efficient Neutral Water Oxidation

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(7)

Published: Oct. 26, 2023

Abstract Neutral oxygen evolution reaction (OER) with unique reactive environments exhibits extremely slow kinetics, posing significant challenges in the design of catalysts. Herein, a built‐in electric field between tungstate (Ni‐FeWO 4 ) adjustable work function and Lewis acid WO 3 is elaborately constructed to regulate asymmetric interfacial electron distribution, which promotes accumulation Fe sites tungstate. This decelerates rapid dissolution under OER potentials, thereby retaining active hydroxyl oxide optimized pathway. Meanwhile, enhances adsorption near electrode surface improve mass transfer. As expected, Ni‐FeWO @WO /NF self‐supporting achieves low overpotential 235 mV at 10 mA cm −2 neutral media maintains stable operation for 200 h. Furthermore, membrane assembly by such robust stability 250 h during seawater electrolysis. deepens understanding reconstruction catalysts paves way development energy conversion technologies.

Language: Английский

---