Developing Ni single-atom sites in carbon nitride for efficient photocatalytic H2O2 production

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

Published: Nov. 6, 2023

Photocatalytic two-electron oxygen reduction to produce high-value hydrogen peroxide (H2O2) is gaining popularity as a promising avenue of research. However, structural evolution mechanisms catalytically active sites in the entire photosynthetic H2O2 system remains unclear and seriously hinders development highly-active stable photocatalysts. Herein, we report high-loading Ni single-atom photocatalyst for efficient synthesis pure water, achieving an apparent quantum yield 10.9% at 420 nm solar-to-chemical conversion efficiency 0.82%. Importantly, using situ synchrotron X-ray absorption spectroscopy Raman directly observe that initial Ni-N3 dynamically transform into high-valent O1-Ni-N2 after O2 adsorption further evolve form key *OOH intermediate before finally forming HOO-Ni-N2. Theoretical calculations experiments reveal structure reduces formation energy barrier suppresses O=O bond dissociation, leading improved production activity selectivity.

Language: Английский

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Sulfone‐Modified Covalent Organic Frameworks Enabling Efficient Photocatalytic Hydrogen Peroxide Generation via One‐Step Two‐Electron O₂ Reduction

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(26)

Published: April 25, 2023

Abstract Photocatalytic oxygen reduction reaction (ORR) offers a promising hydrogen peroxide (H 2 O ) synthetic strategy, especially the one‐step two‐electron (2e − ORR route holds great potential in achieving highly efficient and selectivity. However, 2e is rarely harvested underlying mechanism for regulating pathways remains greatly obscure. Here, by loading sulfone units into covalent organic frameworks (FS‐COFs), we present an photocatalyst H generation via from pure water air. Under visible light irradiation, FS‐COFs exert superb yield of 3904.2 μmol h −1 g , outperforming most reported metal‐free catalysts under similar conditions. Experimental theoretical investigation reveals that accelerate separation photoinduced electron‐hole (e ‐h + pairs, enhance protonation COFs, promote adsorption Yeager‐type, which jointly alters process two‐step to one, thereby with high

Language: Английский

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Engineering the Electronic Structure of Single‐Atom Iron Sites with Boosted Oxygen Bifunctional Activity for Zinc–Air Batteries

Advanced Materials, Journal Year: 2022, Volume and Issue: 35(9)

Published: Dec. 19, 2022

Abstract Rechargeable zinc–air batteries typically require efficient, durable, and inexpensive bifunctional electrocatalysts to support oxygen reduction/evolution reactions (ORR/OER). However, sluggish kinetics mass transportation challenges must be addressed if the performance of these catalysts is enhanced. Herein, a strategy fabricate catalyst comprising atomically dispersed iron atoms supported on mesoporous nitrogen‐doped carbon (Fe SAs/NC) with accessible metal sites optimized electronic metal–support interactions developed. Both experimental results theoretical calculations reveal that engineered structures active can regulate charge distribution Fe centers optimize adsorption/desorption oxygenated intermediates. The SAs/NC containing 1 N 4 O achieves remarkable ORR activity over entire pH range, half‐wave potentials 0.93, 0.83, 0.75 V (vs reversible hydrogen electrode) in alkaline, acidic, neutral electrolytes, respectively. In addition, it demonstrates promising low overpotential 320 mV at 10 mA cm −2 for OER alkaline conditions. battery assembled exhibits superior than Pt/C+RuO 2 counterpart terms peak power density, specific capacity, cycling stability. These findings demonstrate importance structure engineering directing catalytic activity.

Language: Английский

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Electrocatalysts for Zinc–Air Batteries Featuring Single Molybdenum Atoms in a Nitrogen‐Doped Carbon Framework

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

Published: June 16, 2023

Bifunctional catalysts can facilitate two different electrochemical reactions with conflicting characteristics. Here, a highly reversible bifunctional electrocatalyst for rechargeable zinc-air batteries (ZABs) is reported featuring "core-shell structure" in which N-doped graphene sheets wrap around vanadium molybdenum oxynitride nanoparticles. Single Mo atoms are released from the particle core during synthesis and anchored to electronegative N-dopant species graphitic shell. The resultant single-atom excel as active oxygen evolution reaction (OER) sites pyrrolic-N reduction (ORR) pyridinic-N environments. ZABs such multicomponent deliver high power density (≈376.4 mW cm-2 ) long cycle life of over 630 h, outperforming noble-metal-based benchmarks. Flexible that tolerate wide range temperatures (-20 80 °C) under severe mechanical deformation also demonstrated.

Language: Английский

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Review of Carbon Support Coordination Environments for Single Metal Atom Electrocatalysts (SACS)

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(1)

Published: April 20, 2023

This topical review focuses on the distinct role of carbon support coordination environment single-atom catalysts (SACs) for electrocatalysis. The article begins with an overview atomic configurations in SACs, including a discussion advanced characterization techniques and simulation used understanding active sites. A summary key electrocatalysis applications is then provided. These processes are oxygen reduction reaction (ORR), evolution (OER), hydrogen (HER), nitrogen (NRR), dioxide (CO

Language: Английский

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Strategies for Sustainable Production of Hydrogen Peroxide via Oxygen Reduction Reaction: From Catalyst Design to Device Setup

Nano-Micro Letters, Journal Year: 2023, Volume and Issue: 15(1)

Published: May 9, 2023

Abstract An environmentally benign, sustainable, and cost-effective supply of H 2 O as a rapidly expanding consumption raw material is highly desired for chemical industries, medical treatment, household disinfection. The electrocatalytic production route via electrochemical oxygen reduction reaction (ORR) offers sustainable avenue the on-site from O. most crucial innovative part such technology lies in availability suitable electrocatalysts that promote two-electron (2e – ) ORR. In recent years, tremendous progress has been achieved designing efficient, robust, catalyst materials, including noble metals their alloys, metal-free carbon-based single-atom catalysts, molecular catalysts. Meanwhile, cell designs have significantly advanced applications at industrial level. This review summarizes fundamental basics advances 2e -ORR, design, mechanistic explorations, theoretical computations, experimental evaluations, designs. Perspectives on addressing remaining challenges are also presented with an emphasis large-scale synthesis route.

Language: Английский

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Photocatalytic and Electrocatalytic Generation of Hydrogen Peroxide: Principles, Catalyst Design and Performance

Nano-Micro Letters, Journal Year: 2023, Volume and Issue: 15(1)

Published: March 28, 2023

Hydrogen peroxide (H2O2) is a high-demand organic chemical reagent and has been widely used in various modern industrial applications. Currently, the prominent method for preparation of H2O2 anthraquinone oxidation. Unfortunately, it not conducive to economic sustainable development since complex process involves unfriendly environment potential hazards. In this context, numerous approaches have developed synthesize H2O2. Among them, photo/electro-catalytic ones are considered as two most promising manners on-site synthesis These alternatives that only water or O2 required. Namely, oxidation (WOR) oxygen reduction (ORR) reactions can be further coupled with clean energy. For generation, design catalysts extremely important extensively conducted an aim obtain ultimate catalytic performance. This article overviews basic principles WOR ORR, followed by summary recent progresses achievements on performance photo/electro-catalysts generation. The related mechanisms these highlighted from theoretical experimental aspects. Scientific challenges opportunities engineering generation also outlined discussed.

Language: Английский

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Inter-site structural heterogeneity induction of single atom Fe catalysts for robust oxygen reduction

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: March 7, 2024

Abstract Metal-nitrogen-carbon catalysts with hierarchically dispersed porosity are deemed as efficient geometry for oxygen reduction reaction (ORR). However, catalytic performance determined by individual and interacting sites originating from structural heterogeneity is particularly elusive yet remains to be understood. Here, an porous Fe single atom catalyst (Fe SAs-HP) prepared atoms densely resided at micropores mesopores. SAs-HP exhibits robust ORR half-wave potential of 0.94 V turnover frequency 5.99 e −1 s site 0.80 V. Theoretical simulations unravel a induced optimization, where mesoporous Fe-N 4 acts real active centers result long-range electron regulation adjacent microporous sites, facilitating O 2 activation desorption key intermediate *OH. Multilevel operando characterization results identify undergo dynamic evolution basic 3 under working conditions. Our findings reveal the origin enhanced intrinsic activity sites.

Language: Английский

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Single-atom CoN4 sites with elongated bonding induced by phosphorus doping for efficient H2O2 electrosynthesis

Applied Catalysis B Environment and Energy, Journal Year: 2022, Volume and Issue: 324, P. 122267 - 122267

Published: Dec. 5, 2022

Language: Английский

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Surface Energy Mediated Sulfur Vacancy of ZnIn₂S₄ Atomic Layers for Photocatalytic H₂O₂ Production

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(35)

Published: May 14, 2023

Abstract Constructing rich defect active site structure for material design is still a great challenge. Herein, simple surface engineering strategy demonstrated to construct one‐unit‐cell ZnIn 2 S 4 atomic layers with the modulated energy of vacancy. Rich can regulate and control vacancy, which ensures sites, higher charge density effective carrier transport. As result, affords an obvious enhancement in H O productive rate 1592.04 µmol g −1 h , roughly 14.58 times superior that poor energy. Moreover, situ infrared diffuse reflection spectrum indicates vacancy as oxygen reduction reaction responsible critical intermediate *O − *OOH, corresponding two‐electron reaction. This study provides valuable insight guidance constructing controllably defects achieve highly efficient production.

Language: Английский

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