The Hidden Mechanism: Excited‐State Proton‐Electron Pair Transfer in Metal Nanocluster Emission DOI Open Access
Kai‐Yuan Huang,

Yanyan Chen,

Wen‐Lu Wang

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 25, 2024

Abstract Comprehending the underlying factors that govern photoluminescence (PL) in metal nanoclusters (NCs) under physiological conditions remains a highly intriguing and unresolved challenge, particularly for their biomedical applications. In this study, we evaluate critical role of excited‐state proton‐coupled electron transfer emission NCs. Our findings demonstrate hydronium ion (H 3 O + ) binding can trigger nonlinear, pH‐dependent concerted proton (CEPT) reaction. This involves simultaneous from Au(0) core to Au(I)−ATT (ATT denotes 6‐aza‐2‐thiothymidine) surface H ATT ligand single step, greatly promoting vibrations rotations surface, resulting substantial PL quenching Au 10 (ATT) 6 Further analyses show unique CEPT dynamics are strongly influenced by opposing effects increased reorganization energy larger pre‐exponential factor on rate. Moreover, proposed process is found be prevalent core–shell relaxation NCs, such as 25 (SR) 18 (SR thiolate) serves an important limiting emission. By simply controlling p K ligands, performance easily regulated environments.

Language: Английский

Role of Metal Cocatalysts in the Photocatalytic Production of Hydrogen from Water Revisited DOI Creative Commons
Francisco Zaera

Energy & Fuels, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

The use of photocatalysts to promote the production molecular hydrogen from water, following so-called water splitting reaction, continues be a promising route for green fuels. basis this photocatalysis is photoexcitation electrons valence band semiconductors their conduction band, which they can transferred chemical reactants, protons in case reduction reaction. mechanism by such process takes place has been studied extensively using titanium oxide, simple material that fulfills most requirements splitting. However, with TiO2 tends highly inefficient; cocatalyst, commonly late transition metal (Au, Pt) nanoparticle form, needs added facilitate H2. widely believed help scavenging excited semiconductor order prevent recombination accompanying hole formed step cancels initial photon absorption and competes photolytic reduction. Here we review analyze argue an alternative explanation, role atomic atoms produced proton on surface instead. First, summarize what known about electronic structure these how levels need line up feasible. Next, current understanding dynamics steps associated photons, de-excitation via electron–hole pair fluorescence decay, transitions lead reduction, contrast those rates required produce hydrogen. section addresses changes introduced addition comparatively evaluating its as either electron scavenger or promoter atoms. A discussion viable mechanisms latter pathway included. Finally, briefly mention other aspects photocatalysis, including possible promotion H2 visible light resonant excitation plasmon Au nanoparticles, single-metal atom catalysts yolk–shell nanostructures, organic molecules. We end brief personal perspective generality concepts Critical Review.

Language: Английский

Citations

1
Fundamentals of Proton-Insertion Coupled Electron Transfer (PICET) in Metal Oxides for Aqueous Batteries DOI
Noah P. Holzapfel, Veronica Augustyn, Véronique Balland

et al.

ACS Energy Letters, Journal Year: 2025, Volume and Issue: unknown, P. 1143 - 1164

Published: Feb. 10, 2025

Language: Английский

Citations

0
Facile 2D In2Se3 protection for enhanced BiVO4 stability in highly alkaline photoelectrochemical water splitting DOI
Neway Belachew,

Qitao Liu,

Weilong Qin

et al.

Journal of Materials Chemistry A, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Photoelectrochemical (PEC) water splitting holds promise as a major source of sustainable energy production in the future.

Language: Английский

Citations

0
Hydrogen Atom Binding Energy of Structurally Well-Defined Cerium Oxide Nodes at the Metal–Organic Framework–Liquid Interfaces DOI
Zachary Ingram, Chance Lander, Madeleine C. Oliver

et al.

The Journal of Physical Chemistry C, Journal Year: 2024, Volume and Issue: 128(23), P. 9556 - 9565

Published: June 1, 2024

Redox-active metal oxides are prevalent in the fields of thermal, photo-, and electrocatalysis. Thermodynamics proton-coupled electron transfer (PCET) reactions at their surfaces critical, as they scale with activity a catalyst. The free energy H atom binding on catalyst surface is employed catalytic descriptor for H2, O2, many others. structural heterogeneity ambiguity sites have largely precluded understanding exact redox-active sites, challenging chemists to design structure down atomic level. Here, we report electrochemically determined stoichiometry thermodynamics PCET cerium-based metal–organic framework (MOF), Ce-MOF-808. Cyclic voltammograms (CVs) MOF-deposited electrodes aqueous buffers various pHs revealed Faradaic couple that can be ascribed Ce4+/3+ redox. Plotting half-wave potential (E1/2) against electrolyte pH resulted Pourbaix diagram slope 65 ± 9 mV/pH, suggesting 1H+/1e– stoichiometry. Using thermochemical analogy between one (H•), hexanuclear Ce6 node, Ce3+O–H bond dissociation (BDFE), was calculated 78 2 kcal mol–1. In-silico calculations quantitatively corroborated our BDFE measurements. Furthermore, multiple proton topologies were computationally elucidated exhibit BDFEs similar experimental values, agreeing wide features all CVs, implicating system has substantial distribution. To best understanding, this first measurement MOF-liquid interface. Implications presented measurements catalysis using MOFs discussed.

Language: Английский

Citations

3
Nano-TiO2/TiN Systems for Electrocatalysis: Mapping the Changes in Energy Band Diagram across the Semiconductor|Current Collector Interface and the Study of Effects of TiO2 Electrochemical Reduction Using UV Photoelectron Spectroscopy DOI
Beatriz de la Fuente, Divyansh Anil Khurana, Philippe M. Vereecken

et al.

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(37), P. 49926 - 49934

Published: Sept. 4, 2024

TiO

Language: Английский

Citations

3
Lithium-coupled electron transfer reactions of nano-confined WOx within Zr-based metal–organic framework DOI Creative Commons

Hafsa Abdul Ghuffar,

Hyunho Noh

Frontiers in Chemistry, Journal Year: 2024, Volume and Issue: 12

Published: June 14, 2024

Interfacial charge transfer reactions involving cations and electrons are fundamental to (photo/electro) catalysis, energy storage, beyond. Lithium-coupled electron (LCET) at the electrode-electrolyte interfaces of lithium-ion batteries (LIBs) is a preeminent example highlight importance in modern-day society. The thermodynamics LCET define minimal for charge/discharge LIBs, yet, these parameters rarely available literature. Here, we demonstrate successful incorporation tungsten oxides (WO

Language: Английский

Citations

2
Trap States in Reduced Colloidal Titanium Dioxide Nanoparticles Have Different Proton Stoichiometries DOI Creative Commons

Noreen E. Gentry,

Noah J. Gibson, Justin L. Lee

et al.

ACS Central Science, Journal Year: 2024, Volume and Issue: 10(12), P. 2266 - 2273

Published: Nov. 22, 2024

Added electrons and holes in semiconducting (nano)materials typically occupy "trap states," which often determine their photophysical properties chemical reactivity. However, trap states are usually ill-defined, with few insights into stoichiometry or structure. Our laboratory previously reported that aqueous colloidal TiO2 nanoparticles prepared from TiCl4 + H2O have two classes of electron states, termed Blue Red. Herein, we show the formation Red oxidized requires 1e - 1H+, while 2H+. The a protic equilibrium, ⇌ H+, K eq = 2.65 mM. NPs behave just like soluble molecular acid this as a, supported by solvent isotope studies. Because different compositions, population depopulation occur making breaking bonds not (as commonly assumed) movement electrons. In addition, direct observation 2H+/1e state contradicts emerging H atom transfer (1H+/1e -) paradigm for oxide/solution interfaces. Finally, work emphasizes importance stoichiometries, electronic energies, understanding directing reactivity at solid/solution

Language: Английский

Citations

2
Exploring Excited‐State Intramolecular Proton‐Coupled Electron Transfer in Dinuclear Ir(III)‐Complex via Covalently Tagged Hydroquinone: Phototherapy Through Futile Redox Cycling DOI Creative Commons
Maniklal Shee,

Julia Schleisiek,

Nishith Maity

et al.

Small, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 23, 2024

Anticipating intramolecular excited-state proton-coupled electron transfer (PCET) process within dinuclear Ir2-photocatalytic system via the covalent linkage is seminal, yet challenging. Indeed, development of various complexes also promising for studying integral photophysics and facilitating applications in catalysis or biology. Herein, this study reports [Ir2(bis{imidazo-phenanthrolin-2-yl}-hydroquinone)(ppy)4]2+ (12+) complex by leveraging both ligand-centered redox property H-bonding exploring dual proton-transfer assisted PCET process. The vital role covalently placed hydroquinone bridged ligand investigated as electron-proton (ET-PT) mediator validated from triplet spin density plot. Moreover, bimolecular photoinduced ET reaction studied acetonitrile/water medium, forging lowest energy charge separated (3CSPhen-Im) state 12+ with methyl viologen favorably concerted-PCET pathway. result indicates strong donor-acceptors coupling, which limits recombination enhances catalytic efficiency. To showcase potential application, bioinspired PCET-based photocatalytic platform phototherapeutics, indicating significant mitochondrial localization leading to programmed cell death (apoptosis) through futile cycling. consequences effective internalization (via energy-dependent endocytosis), better safety profile, higher antiproliferative activity compared Cisplatin, explored 3D tumor spheroids, anticipates it be a lead compound.

Language: Английский

Citations

2
The Hidden Mechanism: Excited‐State Proton‐Electron Pair Transfer in Metal Nanocluster Emission DOI
Kai‐Yuan Huang,

Yanyan Chen,

Wen‐Lu Wang

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 31, 2024

Comprehending the underlying factors that govern photoluminescence (PL) in metal nanoclusters (NCs) under physiological conditions remains a highly intriguing and unresolved challenge, particularly for their biomedical applications. In this study, we evaluate critical role of excited-state proton-coupled electron transfer emission NCs. Our findings demonstrate hydronium ion (H

Language: Английский

Citations

1
Electrochemically Determined and Structurally Justified Thermochemistry of H atom Transfer on Ti-Oxo Nodes of the Colloidal Metal–Organic Framework Ti-MIL-125 DOI
Nazmiye Gökçe Altınçekiç, Chance Lander, Ayman Roslend

et al.

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(49), P. 33485 - 33498

Published: Oct. 31, 2024

Titanium dioxide (TiO2) has long been employed as a (photo)electrode for reactions relevant to energy storage and renewable synthesis. Proton-coupled electron transfer (PCET) with equimolar amounts of protons electrons at the TiO2 surface or within bulk structure lie center these reactions. Because proton an are thermochemically equivalent H atom, essentially atom Thermodynamics complex dependence on synthetic protocol chemical history electrode, reaction medium, many others; together, complications preclude understanding thermochemistry atomic-level structural knowledge. Herein, we report our success in employing open-circuit potential (EOCP) measurements quantitatively determine structurally well-defined Ti-oxo clusters colloidally stabilized metal–organic framework (MOF), Ti-MIL-125. The free Ti3+O–H bond dissociation (BDFE), was measured be 68(2) kcal mol–1. To best understanding, this is first using EOCP quantify any MOFs. topology, change upon redox reaction, BDFE values were further corroborated computational simulations. Furthermore, comparisons EOCP-derived BDFEs Ti-MIL-125 similar parameters literature suggest that should preferred method accurate calculations. reported nanosized lay ground thermochemical other colloidal systems, which otherwise challenging. Implications acceptor MOFs/metal oxides discussed.

Language: Английский

Citations

1