Single-atom catalysts for photocatalytic energy conversion

Joule, Journal Year: 2022, Volume and Issue: 6(1), P. 92 - 133

Published: Jan. 1, 2022

Artificial photocatalytic energy conversion represents a highly intriguing strategy for solving the crisis and environmental problems by directly harvesting solar energy. The development of efficient photocatalysts is central task pushing real-world application reactions. Due to maximum atomic utilization efficiency distinct advantages outstanding catalytic activity, single-atom catalysts (SACs) have emerged as promising candidates photocatalysts. In current review, recent progresses challenges on SACs systems are presented. Fundamental principles focusing charge separation/transfer molecular adsorption/activation photocatalysis systemically explored. We outline how isolated reactive sites facilitate photogenerated electron–hole transfer promote construction photoactivation cycles. widespread adoption in diverse reactions also comprehensively introduced. By presenting these advances addressing some future with potential solutions related integral over SACs, we expect shed light forthcoming research conversion.

Language: Английский

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Engineering Single-Atom Active Sites on Covalent Organic Frameworks for Boosting CO₂ Photoreduction

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(37), P. 17097 - 17109

Published: Sept. 6, 2022

Solar carbon dioxide (CO2) conversion is an emerging solution to meet the challenges of sustainable energy systems and environmental/climate concerns. However, construction isolated active sites not only influences catalytic activity but also limits understanding structure-catalyst relationship CO2 reduction. Herein, we develop a universal synthetic protocol fabricate different single-atom metal (e.g., Fe, Co, Ni, Zn, Cu, Mn, Ru) anchored on triazine-based covalent organic framework (SAS/Tr-COF) backbone with bridging structure metal-nitrogen-chlorine for high-performance Remarkably, as-synthesized Fe SAS/Tr-COF as representative catalyst achieved impressive CO generation rate high 980.3 μmol g-1 h-1 selectivity 96.4%, over approximately 26 times higher than that pristine Tr-COF under visible light irradiation. From X-ray absorption fine analysis density functional theory calculations, superior photocatalytic performance attributed synergic effect atomically dispersed host, decreasing reaction barriers formation *COOH intermediates promoting adsorption activation well desorption. This work affords rational design state-of-the-art catalysts at molecular level provides in-depth insights efficient conversion.

Language: Английский

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Synergy between Palladium Single Atoms and Nanoparticles via Hydrogen Spillover for Enhancing CO₂ Photoreduction to CH₄

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(16)

Published: Feb. 25, 2022

Selective photoreduction of carbon dioxide (CO2 ) into carbon-neutral fuels such as methane (CH4 is extremely desirable but remains a challenge since sluggish multiple proton-electron coupling transfer and various C1 intermediates are involved. Herein, synergistic function between single Pd atoms (Pd1 nanoparticles (PdNPs on graphitic nitride (C3 N4 for photocatalytic CO2 methanation presented. The catalyst achieves high selectivity 97.8% CH4 production with yield 20.3 µmol gcat.-1 h-1 in pure water. Mechanistic studies revealed that Pd1 sites activated , while PdNPs boosted water (H2 O) dissociation increased H* coverage. produced by migrate to the promote via hydrogen spillover. Moreover, adjacent effectively stabilized *CHO, thereby favoring pathway production. This work provides new perspective development selective conversion through artful design catalytic sites.

Language: Английский

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Metal-metal interactions in correlated single-atom catalysts

Science Advances, Journal Year: 2022, Volume and Issue: 8(17)

Published: April 29, 2022

Single-atom catalysts (SACs) include a promising family of electrocatalysts with unique geometric structures. Beyond conventional ones fully isolated metal sites, an emerging class the adjacent single atoms exhibiting intersite metal-metal interactions appear in recent years and can be denoted as correlated SACs (C-SACs). This type provides more opportunities to achieve substantial structural modification performance enhancement toward wider range electrocatalytic applications. On basis clear identification interactions, this review critically examines research progress C-SACs. It shows that control enables regulation atomic structure, local coordination, electronic properties atoms, which facilitate modulation behavior Last, we outline directions for future work design development C-SACs, is indispensable creating high-performing new SAC architectures.

Language: Английский

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Dual donor-acceptor covalent organic frameworks for hydrogen peroxide photosynthesis

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

Published: Aug. 28, 2023

Constructing photocatalytically active and stable covalent organic frameworks containing both oxidative reductive reaction centers remain a challenge. In this study, benzotrithiophene-based with spatially separated redox are rationally designed for the photocatalytic production of hydrogen peroxide from water oxygen without sacrificial agents. The triazine-containing framework demonstrates high selectivity H2O2 photogeneration, yield rate 2111 μM h-1 (21.11 μmol 1407 g-1 h-1) solar-to-chemical conversion efficiency 0.296%. Codirectional charge transfer large energetic differences between linkages linkers verified in double donor-acceptor structures periodic frameworks. sites mainly concentrated on electron-acceptor fragments near imine bond, which regulate electron distribution adjacent carbon atoms to optimally reduce Gibbs free energy O2* OOH* intermediates during formation H2O2.

Language: Английский

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Atomically Dispersed Indium‐Copper Dual‐Metal Active Sites Promoting C−C Coupling for CO₂ Photoreduction to Ethanol

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(40)

Published: Aug. 10, 2022

Photoreduction of CO2 to C2+ solar fuel is a promising carbon-neutral technology for renewable energy. This strategy challenged by its low productivity due efficiency in multielectron utilization and slow C-C coupling kinetics. work reports dual-metal photocatalyst consisting atomically dispersed indium copper anchored on polymeric carbon nitride (InCu/PCN), which the photoreduction delivered an excellent ethanol production rate 28.5 μmol g-1 h-1 with high selectivity 92 %. Coupled experimental investigation DFT calculations reveal following mechanisms underpinning performance this catalyst. Essentially, In-Cu interaction enhances charge separation accelerating transfer from PCN metal sites. Indium also transfers electrons neighboring via Cu-N-In bridges, increasing electron density active Furthermore, sites promote adsorption *CO intermediates lower energy barrier coupling.

Language: Английский

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Designing covalent organic frameworks with Co-O4 atomic sites for efficient CO2 photoreduction

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

Published: Feb. 28, 2023

Abstract Cobalt coordinated covalent organic frameworks have attracted increasing interest in the field of CO 2 photoreduction to CO, owing their high electron affinity and predesigned structures. However, achieving conversion efficiency is challenging since most Co related coordination environments facilitate fast recombination photogenerated electron-hole pairs. Here, we design two kinds Co-COF catalysts with oxygen atoms find that after tuning environment, reported framework catalyst Co-O 4 sites exhibits a production rate 18000 µmol g −1 h selectivity as 95.7% under visible light irradiation. From in/ex-situ spectral characterizations theoretical calculations, it revealed significantly carrier migration matrixes inhibit pairs photocatalytic process. This work opens way for high-performance photoreduction.

Language: Английский

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Isolating Single and Few Atoms for Enhanced Catalysis

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(39)

Published: May 17, 2022

Abstract Atomically dispersed metal catalysts have triggered great interest in the field of catalysis owing to their unique features. Isolated single or few atoms can be anchored on substrates via chemical bonding space confinement maximize atom utilization efficiency. The key challenge lies precisely regulating geometric and electronic structure active centers, thus significantly influencing catalytic properties. Although several reviews been published preparation, characterization, application single‐atom (SACs), comprehensive understanding SACs, dual‐atom (DACs), atomic clusters has never systematically summarized. Here, recent advances engineering local environments state‐of‐the‐art DACs, for enhanced performance are highlighted. Firstly, various synthesis approaches presented. Then, special attention is focused elucidation terms state coordination structure. Furthermore, a summary isolated applications thermocatalysis, electrocatalysis, photocatalysis provided. Finally, potential challenges future opportunities this emerging This review will pave way regulate microenvironment site boosting processes.

Language: Английский

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Carbon Nitride Photocatalysts with Integrated Oxidation and Reduction Atomic Active Centers for Improved CO₂Conversion

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(34)

Published: June 18, 2022

Single-atom active-site catalysts have attracted significant attention in the field of photocatalytic CO2 conversion. However, designing active sites for reduction and H2 O oxidation simultaneously on a photocatalyst combining corresponding half-reaction system is still difficult. Here, we synthesized bimetallic single-atom with two compatible centers Mn Co carbon nitride (Mn1 Co1 /CN). Our experimental results density functional theory calculations showed that center promotes by accumulating photogenerated holes. In addition, activation increasing bond length angle molecules. Benefiting from synergistic effect atomic centers, Mn1 /CN exhibited CO production rate 47 μmol g-1 h-1 , which significantly higher than single-metal photocatalyst.

Language: Английский

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Crystalline Intramolecular Ternary Carbon Nitride Homojunction for Photocatalytic Hydrogen Evolution

ACS Catalysis, Journal Year: 2022, Volume and Issue: 12(11), P. 6345 - 6358

Published: May 12, 2022

The construction of intramolecular homojunction in the carbon nitride framework is one advantageous methods to improve photocatalytic performance. Based on molecular self-assembly strategy form homojunction, showed enhanced activity. However, disordered structure pristine g-C3N4 obtained using traditional approach inhibits dissociation and migration photocarriers. Here, we adopt a method prepare crystalline C3N4 (HCCN) with functional group modifications ternary by multistep thermal polymerization. band indicates that cyano cyanamide-based units HCCN samples have different highest occupied orbital/lowest unoccupied orbital energy levels, which constitute special through arrangement levels an internal electron field molecule. analysis photoelectron–hole pairs performance confirms accelerates interface charge transfer reduces reverse recombination. Moreover, compact greatly improves photogenerated charges. Femtosecond transient absorption spectra explain trajectory carrier kinetics confirm crystal semiconductor modified groups can promote excitons free This research provides idea obtain homojunctions.

Language: Английский

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