Co₂P-Assisted Atomic Co–N₄ Active Sites with a Tailored Electronic Structure Enabling Efficient ORR/OER for Rechargeable Zn–Air Batteries

ACS Applied Materials & Interfaces, Journal Year: 2023, Volume and Issue: 15(7), P. 9240 - 9249

Published: Feb. 7, 2023

Oxygen reduction and evolution reactions (ORR OER, respectively) are vital steps for metal–air batteries, which plagued by their sluggish kinetics. It is still a challenge to develop highly effective low-cost non-noble-metal-based electrocatalysts. Herein, simple reliable method was reported synthesize Co2P-assisted Co single-atom (Co–N4 centers) electrocatalyst (Co2P/Co-NC) via evaporative drying pyrolysis processes. The Co2P nanoparticles Co–N4 centers uniformly distributed on the nitrogen-doped carbon matrix. Notably, Co2P/Co-NC showed excellent activities in both ORR (initial potential, 1.01 V; half-wave 0.88 V) OER (overpotential, 369 mV at 10 mA cm–2). above results were comparable those of commercial catalysts (such as Pt/C RuO2). Based experimental theoretical analyses, impressive activity can be ascribed tailored electronic structure adjacent Co2P, enabling electron transfer from atom neighboring C atoms, leading downshift d-band center, improved reaction kinetics achieved. assembled Zn–air batteries using air cathode peak power density 187 mW cm–2 long-life cycling stability 140 h 5 cm–2. This work may pave promising avenue design hybrid bifunctional electrocatalysts efficient ORR/OER.

Language: Английский

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Understanding the mechanism and synergistic interaction of cobalt-based electrocatalysts containing nitrogen-doped carbon for 4 e⁻ ORR

Journal of Materials Chemistry A, Journal Year: 2023, Volume and Issue: 11(19), P. 10095 - 10124

Published: Jan. 1, 2023

Considering that the cathodic oxygen reduction reaction (ORR) is sluggish, it necessary to develop efficient and durable catalysts accelerate this reaction.

Language: Английский

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Single‐Atom Nano‐Islands (SANIs): A Robust Atomic–Nano System for Versatile Heterogeneous Catalysis Applications

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(20)

Published: March 26, 2023

Academician Tao Zhang from China and co-workers designed the first Pt1 /FeOx single-atom catalysts (SACs) in 2011, they proposed concept of "single-atom catalysis" field heterogeneous catalysis. Generally, it is easy for active metal sites on a carrier to migrate aggregate, which results poor performance; or chemical bond between atom too strong (immovable), passivation site. Recently, "nano-island" type SACs were designed, atoms are isolated "islands", can move within respective "island", but migration across "island" blocked, achieve dynamic confinement design single (that is, "moving not aggregating" philosophy). Herein, new nano-islands (SANIs)" describe these congeneric "atomic-nano" systems catalysis fields. Particularly, SANIs divided into three categories: "one-island-one-atom", "one-island-multi-atoms", "island-sea synergism" architectures. The scientific significance application principles versatile fields (i.e., thermocatalysis, electrocatalysis, photocatalysis) summarized. challenges proposals also provided.

Language: Английский

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Synergistic Bimetallic CoCu‐Codecorated Carbon Nanosheet Arrays as Integrated Bifunctional Cathodes for High‐Performance Rechargeable/Flexible Zinc‐Air Batteries

Small, Journal Year: 2023, Volume and Issue: 19(17)

Published: Jan. 31, 2023

The unremitting exploration of well-architectured and high-efficiency oxygen electrocatalysts is promising to speed up the surface-mediated reduction/evolution reaction (ORR/OER) kinetics rechargeable zinc-air batteries (ZABs). Herein, bimetallic CoCu-codecorated carbon nanosheet arrays (CoCu/N-CNS) are proposed as self-supported bifunctional catalysts. integrated catalysts in situ constructed via a simple sacrificial-templated strategy, imparting CoCu/N-CNS with 3D interconnected conductive pathways, abundant mesopores for electrolyte penetration ion diffusion, well Cu-synergized Co-Nx /O reactive sites improved catalytic activities. By incorporating moderate amount Cu into CoCu/N-CNS, activities can be further increased due synergistic electrocatalysis. Consequently, optimized realizes low overall overpotential 0.64 V OER ORR leads high-performance liquid ZABs high gravimetric energy (879.7 Wh kg-1 ), peak power density (104.3 mW cm-2 remarkable cyclic stability upon 400 h/1000 cycles at 10 mA . More impressively, all-solid-state flexible assembled cathode exhibit superior rate performance exceptional mechanical flexibility under arbitrary bending conditions. This monolith holds significant potential advancing cation-modulated multimetallic multifunctional nanocatalysts.

Language: Английский

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Design strategies towards transition metal single atom catalysts for the oxygen reduction reaction – A review

Deleted Journal, Journal Year: 2023, Volume and Issue: 2, P. e9120082 - e9120082

Published: May 31, 2023

The electrochemical oxygen reduction reaction (ORR) is pivotal in energy conversion via a 4e⁻ ORR pathway and green hydrogen peroxide production 2e⁻ pathway. Transition metal single atom catalysts (TM SACs) have attracted intense attention recent years for due to their high activity near maximum utilization. future development of TM SACs requires improved understanding pathways, since currently the true origin remains contentious owing lack qualitative/quantitative information about active sites. Knowledge-guided design imperative optimization performance terms selectivity. This review focuses on latest progress ORR, placing particular efforts elucidate mechanisms. Experimental evidence based in-situ/operando characterization measurements, along with theoretical predictions, are summarized deepen structure-performance relationships at both atomic molecular level. Finally, some perspectives offered relating fundamental science needed find practical application storage devices. We hope this will inspire new synthetic routes towards high-performance electrocatalysts sector.

Language: Английский

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