Facet Engineering of Advanced Electrocatalysts Toward Hydrogen/Oxygen Evolution Reactions

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Фев. 16, 2023

The electrocatalytic water splitting technology can generate high-purity hydrogen without emitting carbon dioxide, which is in favor of relieving environmental pollution and energy crisis achieving neutrality. Electrocatalysts effectively reduce the reaction barrier increase efficiency. Facet engineering considered as a promising strategy controlling ratio desired crystal planes on surface. Owing to anisotropy, with different orientations usually feature facet-dependent physical chemical properties, leading differences adsorption energies oxygen or intermediates, thus exhibit varied activity toward evolution (HER) (OER). In this review, brief introduction basic concepts, fundamental understanding mechanisms well key evaluating parameters for both HER OER are provided. formation facets comprehensively overviewed aiming give scientific theory guides realize dominant planes. Subsequently, three strategies selective capping agent, etching coordination modulation tune summarized. Then, we present an overview significant contributions facet-engineered catalysts HER, OER, overall splitting. particular, highlight that density functional calculations play indispensable role unveiling structure–activity correlation between plane catalytic activity. Finally, remaining challenges provided future prospects designing advanced electrocatalysts discussed.

Язык: Английский

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Mutual Self-Regulation of d-Electrons of Single Atoms and Adjacent Nanoparticles for Bifunctional Oxygen Electrocatalysis and Rechargeable Zinc-Air Batteries

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Фев. 11, 2023

Rechargeable zinc-air batteries (ZABs) are a promising energy conversion device, which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction (ORR) and evolution (OER). Herein, we fabricate range of bifunctional M-N-C (metal-nitrogen-carbon) catalysts containing M-Nx coordination sites M/MxC nanoparticles (M = Co, Fe, Cu) using new class γ-cyclodextrin (CD) based metal-organic framework the precursor. With two types active interacting with each other in catalysts, obtained Fe@C-FeNC Co@C-CoNC display superior alkaline ORR activity terms low half-wave (E1/2) potential (~ 0.917 0.906 V, respectively), higher than Cu@C-CuNC 0.829 V) commercial Pt/C 0.861 V). As electrocatalyst, exhibits best performance, showing ORR/OER overpotential (ΔE) ~ 0.732 is much lower that 0.831 1.411 V), well most robust reported date. Synchrotron X-ray absorption spectroscopy density functional theory simulations reveal strong electronic correlation between metallic Co atomic Co-N4 catalyst can increase d-electron near Fermi level thus effectively optimize adsorption/desorption intermediates ORR/OER, resulting an enhanced electrocatalytic performance. The Co@C-CoNC-based rechargeable ZAB exhibited maximum power 162.80 mW cm-2 at 270.30 mA cm-2, combination + RuO2 158.90 265.80 cm-2) catalysts. During galvanostatic discharge 10 delivered almost stable voltage 1.2 V for 140 h, signifying virtue excellent activity.

Язык: Английский

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Principles of Design and Synthesis of Metal Derivatives from MOFs

Advanced Materials, Год журнала: 2023, Номер 35(24)

Опубликована: Янв. 10, 2023

Abstract Materials derived from metal–organic frameworks (MOFs) have demonstrated exceptional structural variety and complexity can be synthesized using low‐cost scalable methods. Although the inherent instability low electrical conductivity of MOFs are largely responsible for their uptake catalysis energy storage, a superior alternative is MOF‐derived metal‐based derivatives (MDs) as these retain complex nanostructures while exhibiting stability conductivities several orders magnitude higher. The present work comprehensively reviews MDs in terms synthesis nanostructural design, including oxides, sulfides, phosphides, nitrides, carbides, transition metals, other minor species. focal point approach identification rationalization design parameters that lead to generation optimal compositions, structures, nanostructures, resultant performance parameters. aim this provide an inclusive platform strategies process materials specific applications. This complemented by detailed figures both summarize processing approaches been reported indicate potential trajectories development. also supported comprehensive up‐to‐date tabular coverage studies.

Язык: Английский

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A Review of In-Situ Techniques for Probing Active Sites and Mechanisms of Electrocatalytic Oxygen Reduction Reactions

Nano-Micro Letters, Год журнала: 2022, Номер 15(1)

Опубликована: Дек. 29, 2022

Electrocatalytic oxygen reduction reaction (ORR) is one of the most important reactions in electrochemical energy technologies such as fuel cells and metal-O2/air batteries, etc. However, essential catalysts to overcome its slow kinetic always undergo a complex dynamic evolution actual catalytic process, concomitant intermediates products also occur continuous conversion reconstruction. This makes them difficult be accurately captured, making identification ORR active sites elucidation mechanisms difficult. Thus, it necessary use extensive in-situ characterization techniques proceed real-time monitoring catalyst structure state during ORR. work reviews major advances various characterize processes catalysts. Specifically, evolutions revealed directly by are systematically summarized, phase, valence, electronic transfer, coordination, spin states varies. In-situ revelation intermediate adsorption/desorption behavior, product nucleation, growth, reconstruction equally emphasized discussion. Other interference factors, well signal assignment with aid theoretical calculations, covered. Finally, some challenges prospects for future research process proposed.

Язык: Английский

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Aerophilic Triphase Interface Tuned by Carbon Dots Driving Durable and Flexible Rechargeable Zn-Air Batteries

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Янв. 3, 2023

Efficient bifunctional catalysts for oxygen reduction reaction (ORR) and evolution (OER) are vital rechargeable Zn-air batteries (ZABs). Herein, an oxygen-respirable sponge-like Co@C-O-Cs catalyst with oxygen-rich active sites was designed constructed both ORR OER by a facile carbon dot-assisted strategy. The aerophilic triphase interface of cathode efficiently boosts diffusion transfer. theoretical calculations experimental studies revealed that the Co-C-COC can redistribute local charge density lower energy barrier. displays superior catalytic activities half-wave potential 0.82 V ultralow overpotential 294 mV at 10 mA cm-2 OER. Moreover, it drive liquid ZABs high peak power (106.4 mW cm-2), specific capacity (720.7 mAh g-1), outstanding long-term cycle stability (over 750 cycles exhibits excellent feasibility in flexible all-solid-state ZABs. These findings provide new insights into rational design efficient metal-air batteries.

Язык: Английский

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Electronic modulation induced by decorating single-atomic Fe-Co pairs with Fe-Co alloy clusters toward enhanced ORR/OER activity

Applied Catalysis B Environment and Energy, Год журнала: 2023, Номер 340, С. 123231 - 123231

Опубликована: Авг. 29, 2023

Язык: Английский

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Heteroatom-Induced Accelerated Kinetics on Nickel Selenide for Highly Efficient Hydrazine-Assisted Water Splitting and Zn-Hydrazine Battery

Nano-Micro Letters, Год журнала: 2023, Номер 15(1)

Опубликована: Июнь 19, 2023

Hydrazine-assisted water electrolysis is a promising energy conversion technology for highly efficient hydrogen production. Rational design of bifunctional electrocatalysts, which can simultaneously accelerate evolution reaction (HER)/hydrazine oxidation (HzOR) kinetics, the key step. Herein, we demonstrate development ultrathin P/Fe co-doped NiSe2 nanosheets supported on modified Ni foam (P/Fe-NiSe2) synthesized through facile electrodeposition process and subsequent heat treatment. Based electrochemical measurements, characterizations, density functional theory calculations, favorable "2 + 2" mechanism with two-step HER HzOR step was fully proved specific effect P doping kinetics investigated. P/Fe-NiSe2 thus yields an impressive electrocatalytic performance, delivering high current 100 mA cm-2 potentials - 168 200 mV HzOR, respectively. Additionally, work efficiently hydrazine-assisted Zn-Hydrazine (Zn-Hz) battery, making it practical application.

Язык: Английский

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Engineering d-band center of FeN4 moieties for efficient oxygen reduction reaction electrocatalysts

Energy storage materials, Год журнала: 2023, Номер 59, С. 102764 - 102764

Опубликована: Апрель 6, 2023

Atomically-dispersed FeN4 moieties are emerging as low-cost electrocatalysts for oxygen reduction reaction (ORR), which can be applied in fuel cells and metal-air batteries. Whereas, the unsatisfactory position of d-band center from metal sites offered by affects adsorption-desorption behaviors oxygenated intermediates, further impeding improvement their ORR performances. Herein, we report a well-designed diatomic Fe/Zn-CNHC catalyst on microporous hollow support. This strategy drives Fe upward, thus making active more favorable stable during kinetic processes. The material exhibits an excellent activity with half-wave potential 0.91 V stability (insignificant attenuation after 5,000 cycles), surpassing commercial Pt/C many other single-atom catalysts. DFT calculations indicate that tuning effect Zn d-orbital electron distribution facilitates stretching cleavage Fe-O, accelerating rate-determining step. work presents simple to fabricate well-defined coordination inspires future research developing new syntheses control electrocatalysts.

Язык: Английский

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Interface and doping engineering of Co-based electrocatalysts for enhanced oxygen reduction and evolution reactions

Chemical Engineering Journal, Год журнала: 2023, Номер 470, С. 144380 - 144380

Опубликована: Июнь 25, 2023

Язык: Английский

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One‐Pot Etching Pyrolysis to Defect‐Rich Carbon Nanosheets to Construct Multiheteroatom‐Coordinated Iron Sites for Efficient Oxygen Reduction

Small, Год журнала: 2024, Номер 20(33)

Опубликована: Апрель 9, 2024

Constructing multiheteroatom coordination structure in carbonaceous substrates demonstrates an effective method to accelerate the oxygen reduction reaction (ORR) of supported single-atom catalyst. Herein, novel etching route assisted by potassium thiocyanate (KCNS) is developed convert metal-organic framework 2D defect-rich porous N,S-co-doped carbon nanosheets for anchoring atomically dispersed iron sites as high-performance ORR catalysts (Fe-SACs). The well-designed KCNS-assisted can generate spatial confinement template direct nanosheet formation, condition form structure, and additional sulfur atoms coordinate species. Spectral microscopy analysis reveals that element Fe-SACs highly isolated on anchored nitrogen unsymmetrical Fe-S

Язык: Английский

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