Atomically Dispersed Metal–Nitrogen–Carbon Catalysts with d-Orbital Electronic Configuration-Dependent Selectivity for Electrochemical CO₂-to-CO Reduction

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(4), P. 2374 - 2385

Published: Feb. 1, 2023

A variety of atomically dispersed transition-metal-anchored nitrogen-doped carbon (M–N–C) electrocatalysts have shown encouraging electrochemical CO2 reduction reaction (CO2RR) performance, with the underlying fundamentals central transition-metal atom determined CO2RR activity and selectivity yet remaining unclear. Herein, a universal impregnation-acid leaching method was exploited to synthesize various M–N–C (M: Fe, Co, Ni, Cu) single-atom catalysts (SACs), which revealed d-orbital electronic configuration-dependent toward for CO production. Notably, Ni–N–C exhibits very high Faradaic efficiency (FE) 97% at −0.65 V versus RHE above 90% in potential range from −0.5 −0.9 RHE, much superior other Cu). With configurations metals SACs well elucidated by crystal-field theory, Dewar–Chatt–Duncanson (DCD) differential charge density analysis reveal that vacant outermost Ni2+ SAC would benefit electron transfer C atoms molecules Ni thus effectively activate surface-adsorbed molecules. However, Fe3+, Co2+, Cu2+ occupied unpaired electrons weaken electron-transfer process then impede activation. In situ spectral investigations demonstrate generation *COOH intermediates is favored over relatively low applied potentials, supporting its CO2-to-CO conversion performance. Gibbs free energy difference rate-limiting step hydrogen evolution (HER) reveals thermodynamically SAC, explaining performance as compared SACs. This work presents facile general strategy modulate perspective configuration

Language: Английский

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Ultrathin covalent organic framework nanosheets for enhanced photocatalytic water oxidation

Science Advances, Journal Year: 2024, Volume and Issue: 10(3)

Published: Jan. 17, 2024

Photocatalytic water oxidation is a key half-reaction for various solar-to-fuel conversion systems but requires simultaneous affinity and hole accumulation at the photocatalytic site. Here, we present rational design synthesis of an ionic-type covalent organic framework (COF) named tetraphenylporphyrin cobalt bipyridine complex (CoTPP-CoBpy 3 ) COF, combining porphyrin building blocks as photocatalyst oxidation. The good dispersibility porous large-size (>2 micrometers) COF nanosheets (≈1.45 nanometers) facilitates local collection; ultrafast triplet-state charge transfer (1.8 picoseconds) prolonged separation (1.2 nanoseconds) further contribute to efficient holes in CoTPP moiety, leading dioxygen production rate 7323 micromoles per gram hour. Moreover, have identified end-on superoxide radical (O 2 · intermediate active site moiety proposed electron-intermediate cascade mechanism that elucidates synergistic coupling electron relay (S 1 -T ′) evolution during process.

Language: Английский

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Defect Engineering Simultaneously Regulating Exciton Dissociation in Carbon Nitride and Local Electron Density in Pt Single Atoms Toward Highly Efficient Photocatalytic Hydrogen Production

Small, Journal Year: 2024, Volume and Issue: 20(34)

Published: April 10, 2024

Abstract The high exciton binding energy ( E b ) and sluggish surface reaction kinetics have severely limited the photocatalytic hydrogen production activity of carbon nitride (CN). Herein, a hybrid system consisting nitrogen defects Pt single atoms is constructed through facile self‐assembly photodeposition strategy. Due to acceleration dissociation regulation local electron density along with introduction defects, optimized Pt‐MCT‐3 exhibits rate 172.0 µmol h −1 λ ≥ 420 nm), ≈41 times higher than pristine CN. apparent quantum yield for determined be 27.1% at nm. experimental characterizations theoretical calculations demonstrate that act as traps dissociation, resulting in decrease from 86.92 43.20 meV. Simultaneously, stronger interaction between neighboring directionally drives free electrons aggregate around atoms, tailors d ‐band Pt, forming moderate strength H* intermediates.

Language: Английский

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Photocatalytic H2O2 production over boron-doped g-C3N4 containing coordinatively unsaturated FeOOH sites and CoOx clusters

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

Published: Oct. 25, 2024

Graphitic carbon nitride (g-C

Language: Английский

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Recent progress in perylene diimide supermolecule-based photocatalysts

Journal of Materials Chemistry A, Journal Year: 2024, Volume and Issue: 12(7), P. 3807 - 3843

Published: Jan. 1, 2024

This review focuses on recent advancements in perylene diimide supramolecular (PDI)-based photocatalysts.

Language: Английский

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Interfacial interaction-induced shift of d-band center promotes photocatalytic antibiotics mineralization

Applied Catalysis B Environment and Energy, Journal Year: 2024, Volume and Issue: 352, P. 123998 - 123998

Published: April 21, 2024

Language: Английский

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Electron-Deficient Zn-N6 Configuration Enabling Polymeric Carbon Nitride for Visible-Light Photocatalytic Overall Water Splitting

Nano-Micro Letters, Journal Year: 2022, Volume and Issue: 14(1)

Published: Nov. 14, 2022

Abstract Despite of suitable band structures for harvesting solar light and driving water redox reactions, polymeric carbon nitride (PCN) has suffered from poor charge transfer ability sluggish surface reaction kinetics, which limit its photocatalytic activity splitting. Herein, atomically dispersed Zn-coordinated three-dimensional (3D) sponge-like PCN (Zn-PCN) is synthesized through a novel intermediate coordination strategy. Advanced characterizations theoretical calculations well evidence that Zn single atoms are coordinated stabilized on in the form Zn-N 6 configuration featured with an electron-deficient state. Such electronic been demonstrated contributive to promoted electron excitation, accelerated separation as reduced barriers. Further benefited abundant active sites derived 3D porous structure, Zn-PCN realizes visible-light photocatalysis overall splitting H 2 O simultaneously evolved at stoichiometric ratio 2:1. This work brings new insights into design single-atom photocatalysts by deepening understanding configurations reactive favorable excellent related energy conversion reactions. "Image missing"

Language: Английский

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Red Phosphorus Grafted High‐Index (116) Faceted Anatase TiO₂ for Z‐Scheme Photocatalytic Pure Water Splitting

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 34(9)

Published: Nov. 20, 2023

Abstract Red phosphorus (RP) is an emerging visible‐light‐responsive photocatalyst, yet the rapid charge recombination has limited photocatalytic hydrogen production activity. In this work, a Z‐scheme heterostructure with RP nanolayer coated on high‐index (116) faceted anatase TiO 2 nanoparticles (TiO @RP) designed and fabricated via chemical vapor deposition. Compared pristine RP, optimized @RP exhibits significantly boosted activity for pure water splitting, evolution rate reaching 12.9 µmol·h −1 , under simulated solar light irradiation. The strong interfacial interaction staggered band alignment between result in formation of built‐in electric field, which can drive directional migration from conduction (CB) to valance (VB) irradiation, photoelectrons holes high redox ability maintained at CB VB respectively. This well‐designed greatly promotes photogenerated separation direct transfer pathway.

Language: Английский

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Photoinduced Hydration Boosts O₂ Evolution on Co-Chelating Covalent Organic Framework

ACS Energy Letters, Journal Year: 2023, Volume and Issue: 8(4), P. 1857 - 1863

Published: March 22, 2023

The achievement of artificial photosynthesis relies on successful water oxidation and a detailed mechanistic understanding. Here, we demonstrate photoinduced hydration pathway for O2 evolution from over an imine-linked covalent organic framework (COF) comprising electron-rich benzotrithiophene electron-deficient benzothiadiazole units with atomically chelated Co sites. experimental theoretical results suggest that the starts imine groups. subsequent oxidative deprotonation intramolecular hydroxyl attack lead to O–O bond formation. path significantly averages energy barriers oxidation, thus promoting evolution. Inspired by this fact, fabricate COF-based heterostructure, which realizes overall splitting H2 rates 450 212 μmol·g–1 h–1, respectively.

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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