Benchmarking the Intrinsic Activity of Transition Metal Oxides for the Oxygen Evolution Reaction with Advanced Nanoelectrodes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(23)

Published: April 5, 2024

Abstract The intrinsic activity assessment of transition metal oxides (TMOs) as key electrocatalysts for the oxygen evolution reaction (OER) has not been standardized due to uncertainties regarding their structure and composition, difficulties in accurately measuring electrochemically active surface area (ECSA), deficiencies mass‐transfer (MT) rates conventional measurements. To address these issues, we utilized an electrodeposition‐thermal annealing method precisely synthesize single‐particle TMOs with well‐defined composition. Concurrently, engineered low roughness, spherical surfaces individual particles, enabling precise measurement ECSA. Furthermore, by constructing a conductor‐core semiconductor‐shell structure, evaluated inherent OER perovskite‐type semiconductor materials, broadening scope beyond just conductive TMOs. Finally, using nanoelectrode technique, systematically measured TMO particles various sizes OER, overcoming MT limitations seen approaches. These improvements have led us propose reliable approach evaluating TMOs, only validating accuracy theoretical calculations but also revealing strong correlation on melting point This discovery holds significant importance future high‐throughput material research applications, offering valuable insights electrocatalysis.

Language: Английский

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Decoupling of the Confused Complex in Oxidation of 3,3′,5,5′-Tetramethylbenzidine for the Reliable Chromogenic Bioassay

Analytical Chemistry, Journal Year: 2023, Volume and Issue: 95(44), P. 16407 - 16417

Published: Oct. 26, 2023

Regulation of the reaction pathways is a perennial theme in field chemistry. As typical chromogenic substrate, 3,3′,5,5′-tetramethylbenzidine (TMB) generally undertakes one-electron oxidation, but product (TMBox1) essentially confused complex and unstable, which significantly hampers clinic bioassays for more than 50 years. Herein, we report that sodium dodecyl sulfate (SDS)-based micelles could drive direct two-electron oxidation TMB to final stable TMBox2. Rather activation H2O2 oxidant by common natural peroxidase, substrate SDS decoupled thermodynamically favorable between TMBox2 with unreacted TMB, leading an unusual pathway. Mechanism studies demonstrated complementary spatial electrostatic isolation effects, caused confined hydrophobic cavities negatively charged outer surfaces micelles, were crucial. Further cascading glucose oxidase, as proof-of-concept application, allowed be reliably measured, even broader range concentrations without any conventional strong acid termination.

Language: Английский

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Transformative Personalized Oxalate Biomarker Analysis through a Wrist-Worn Microneedle Device Integrated with Duplex Nanozyme Toolbox

Sensors and Actuators B Chemical, Journal Year: 2024, Volume and Issue: 423, P. 136731 - 136731

Published: Oct. 9, 2024

Language: Английский

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2,2′‐Thienoviologens with Low Reduction Potential for Electrochromism and Visible‐Light‐Driven Hydrogen Evolution Using g‐C₃N₄‐Based Composites via Hydrogen Bonds

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: 14(26)

Published: May 8, 2024

Abstract A series of sulfur‐bridged 2,2′‐viologens, 2,2′‐thienoviologens (2,2′‐SV 2+ ) with propyl bridge and hydroxyl bridges, are synthesized for the first time. The exhibited improved visible‐light absorption, narrow energy gap, more negative reduction potential (160 mV lower than 4,4′‐thienoviologens) stable free radical states compared 4,4′‐thienoviologens parent 2,2′‐viologens. utilization femtosecond transient absorption (fs‐TA) demonstrated that 2,2′‐thienoviologen can produce distinct charge‐separated under visible light excitation. Due to their excellent photophysical electrochemical properties, used electrochromic devices combined g‐C 3 N 4 via hydrogen bonds catalytic production. Based on advantageous electron‐donating properties 2,2′‐SV , release efficiency 2,2′‐thienoviologens‐modified composites is 8542 µmol·h −1 ·g a value highest reported production from organic small‐molecule‐modified 78 times higher unmodified . This study presents concise method convert solar broaden applications 2,2′‐viologens in photocatalytic systems.

Language: Английский

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From Molecular Electronics to Molecular Intelligence

ACS Nano, Journal Year: 2024, Volume and Issue: 18(42), P. 28531 - 28556

Published: Oct. 12, 2024

Molecular electronics is a field that explores the ultimate limits of electronic device dimensions by using individual molecules as operable devices. Over past five decades since proposal molecular rectifier Aviram and Ratner in 1974 ( Chem. Phys. Lett.1974,29, 277−283), researchers have developed various fabrication characterization techniques to explore electrical properties molecules. With push characterizations data analysis methodologies, reproducibility issues single-molecule conductance measurement been chiefly resolved, origins variation among different devices investigated. Numerous prototypical with external physical chemical stimuli demonstrated based on advances instrumental methodological developments. These enable functions such switching, logic computing, synaptic-like computing. However, goal electronics, how can molecular-based intelligence be achieved through devices? At fiftieth anniversary we try answer this question summarizing recent progress providing an outlook electronics. First, review methodologies for junctions, which provide foundation Second, preliminary efforts toward integration circuits are discussed future potential intelligent applications. Third, some sensing applications introduced, demonstrating phenomena at scale beyond conventional macroscopic From perspective, summarize current challenges prospects describing concepts "AI electronics" "single-molecule AI".

Language: Английский

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Organic radicals in single-molecule junctions

Science China Materials, Journal Year: 2024, Volume and Issue: 67(3), P. 709 - 728

Published: Feb. 22, 2024

Language: Английский

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Tracking Noncovalent Interactions of π, π-Hole, and Ion in Molecular Complexes at the Single-Molecule Level

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(36), P. 25290 - 25298

Published: Aug. 28, 2024

Noncovalent interactions involving aromatic rings, such as π-stacking and π-ion interactions, play an essential role in molecular recognition, assembly, catalysis, electronics. However, the inherently weak complex nature of these has made it challenging to study them experimentally, especially with regard elucidating their properties solution. Herein, noncovalent between π π-hole, cation, π-hole anion complexes nonpolar solution are investigated situ through single-molecule electrical measurements combination theoretical calculations. Specifically, phenyl pentafluorobenzyl groups serve sites, respectively, while Li+ Cl– employed cation anion. Our findings reveal that, comparison homogeneous π···π heterogeneous π···π-hole π···cation exhibit greater binding energies, resulting a longer lifetime junctions. Meanwhile, π···Li+ π-hole···Cl– present significantly distinct characteristics, former being stronger but more flexible than latter. Furthermore, by changing components, similar conductivity can be achieved both dimers or sandwich complexes. These results provide new insights into π- π-hole-involved offering novel strategies for precise manipulation device.

Language: Английский

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Radical-Induced Single-Molecule Conductance Tuning in 9,9'-Bifluorenylidene Derivatives

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A series of 9,9′-bifluorenylidene derivatives demonstrate orthogonalization non-conducting (between radical sites) and conducting thiomethyl groups) paths. Precise injections significantly reduce single-molecule conductance.

Language: Английский

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Digging through the (Statistical) Dirt: A Reproducible Method for Single-Molecule Flicker Noise Analysis

The Journal of Physical Chemistry C, Journal Year: 2025, Volume and Issue: 129(8), P. 4097 - 4104

Published: Feb. 14, 2025

Flicker noise analysis has found widespread use in the molecular electronics community over past 9 years. The power of junctions and value its scaling exponent n provide information on spatial overlap scattering states single-molecule give unique insights into quantum transport phenomena at level. predominant drawback this analytical tool is inconsistency methodologies employed, resulting irreproducibility across data sets acquired different conditions or laboratories. Herein, we a pathway to more reproducible methodology, detailing issues with currently accepted correlation techniques employed introducing statistically robust processing criteria lower thresholds for acquisition parameters.

Language: Английский

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Electronically Perturbed Vibrational Excitations of the Luminescing Stable Blatter Radical

ACS Nano, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 21, 2025

Stable radicals are spin-active species with a plethora of proposed applications in fields from energy storage and molecular electronics to quantum communications. However, their optical properties vibrational modes so far not well understood. Furthermore, it is yet clear how these affected by the radical oxidation state, which key understanding electronic transport. Here, we identify 1,2,4-benzotriazin-4-yl, stable doubly thiolated variant Blatter radical, using surface-enhanced Raman scattering (SERS). Embedding monolayers plasmonic nanocavities gives access modes, photoluminescence, response during redox processes. We reveal influence adjacent metallic surfaces fluctuating SERS signals that suggest coupling between unpaired electron spatially overlapping mode. This can potentially be exploited for information-storage devices chemically designed qubits.

Language: Английский

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