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1.
J Multidiscip Healthc ; 17: 4243-4256, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39228515

RESUMEN

Background: Clinical acupuncture decisions are highly operator-dependent and require physician-patient interactions. The Delphi method allows subjective factors such as expert experience and preference of patients to be taken into account in clinical decision making, which is particularly applicable to acupuncture. Currently, the Delphi method is widely used to support clinical decisions in acupuncture. Therefore, it is necessary to provide high-quality and complete descriptions of the Delphi process when making clinical decisions. This study aims to evaluate the quality of the Delphi process in acupuncture, facilitate its standardization and rigor for further clinical decision making in acupuncture. Methods: Articles sourced from six databases were searched systematically to assess the quality of the Delphi consensus process based on the standards for conducting and reporting Delphi studies (CREDES). Descriptive statistics and analysis were presented according to the percentage of each item. Five-score Likert scale was used to evaluate the reporting quality of four domains as well as each item in CREDES by two independent researchers, combined with ICC-value to assess the consistency. Results: A total of 37 qualified articles were included according to eligibility criteria. As for the low reporting rate, the item "External validation" was reported as the lowest positive rate at 32.43% and the item "Prevention of bias" was 48.65%. The item "Adequacy of conclusions", "Definition and attainment of consensus", and "Discussion of limitations" were reported at a positive ratio of 62.16%, 64.86%, and 67.57% individually. The average scores of the four domains based on CREDES from highest to lowest were, respectively, as follows: planning and design (68.75%), reporting (66.07%), rationale for the choice of the Delphi technique (65.54%), study conduct (45.10%). Conclusion: The reporting quality of the Delphi consensus process in acupuncture is acceptable currently, but the reporting rate on some items is still low. Further standardization, including either clearer checklists or study reports, should be developed and strengthened to guide clinical decisions in acupuncture.

2.
J Phys Chem Lett ; 15(31): 7939-7944, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39074357

RESUMEN

We report chemical vapor deposition (CVD) synthesis of two quasi-one-dimensional (quasi-1D) polymorphs of BiSCl, denoted by y-BiSCl and r-BiSCl. The length of the CVD samples can reach about 0.4 mm. Such quasi-1D samples of the two polymorphs can be readily separated into individual pieces for either characterization or application. The two polymorphs can be clearly differentiated by Raman spectroscopy. First-principles calculations and group analysis are used to assign each Raman peak to the corresponding vibrational mode. Ultraviolet-visible measurements on solution grown thin-film samples reveal that the two polymorphs exhibit significantly different band gaps of 2.08 eV (y-BiSCl) and 1.81 eV (r-BiSCl). First-principles calculation further shows that the interatomic chain binding energy is 18.1 meV/Å2, confirming that the van der Waals stacking determines the difference in their band gaps. Our findings highlight the possibility of realizing the desired functionalities in quasi-1D materials by controlling stacking orientation.

3.
Chem Sci ; 15(23): 8835-8840, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38873051

RESUMEN

High yields of C2 products through electrocatalytic CO2 reduction (eCO2R) can only be obtained using Cu-based catalysts. Here, we adopt the generalized frontier molecular orbital (MO) theory based on first-principles calculations to identify the origin of this unique property of Cu. We use the grand canonical ensemble (or fixed potential) approach to ensure that the calculated Fermi level, which serves as the frontier orbital of the metal catalyst, accurately represents the applied electrode potentials. We determine that the key intermediate OCCO assumes a U-shape configuration with the two C atoms bonded to the Cu substrate. We identify the frontier MOs that are involved in the C-C coupling. The good alignment of the Fermi level of Cu with these frontier MOs is perceived to account for the excellent catalytic performance of Cu for C-C coupling. It is expected that these new insights could provide useful guidance in tuning Cu-based catalysts as well as designing non-Cu catalysts toward high-efficiency eCO2R.

4.
Molecules ; 29(4)2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38398519

RESUMEN

To enhance the bioavailability and antihypertensive effect of the anti-depressant drug citalopram hydrobromide (CTH) we developed a sustained-release transdermal delivery system containing CTH. A transdermal diffusion meter was first used to determine the optimal formulation of the CTH transdermal drug delivery system (TDDS). Then, based on the determined formulation, a sustained-release patch was prepared; its physical characteristics, including quality, stickiness, and appearance, were evaluated, and its pharmacokinetics and irritation to the skin were evaluated by applying it to rabbits and rats. The optimal formulation of the CTH TDDS was 49.2% hydroxypropyl methyl cellulose K100M, 32.8% polyvinylpyrrolidone K30, 16% oleic acid-azone, and 2% polyacrylic acid resin II. The system continuously released an effective dose of CTH for 24 h and significantly enhanced its bioavailability, with a higher area under the curve, good stability, and no skin irritation. The developed CTH TDDS possessed a sustained-release effect and good characteristics and pharmacokinetics; therefore, it has the potential for clinical application as an antidepressant.


Asunto(s)
Citalopram , Absorción Cutánea , Ratas , Conejos , Animales , Citalopram/farmacología , Citalopram/metabolismo , Preparaciones de Acción Retardada/farmacología , Administración Cutánea , Piel , Sistemas de Liberación de Medicamentos , Parche Transdérmico
5.
J Phys Chem Lett ; 14(50): 11342-11349, 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38064589

RESUMEN

Two challenges facing machine learning tasks in materials science are data set construction and descriptor design. Graph neural networks circumvent the need for empirical descriptors by encoding geometric information in graphs. Large language models have shown promise for database construction via text extraction. Here, we apply OpenAI's Generative Pre-trained Transformer 4 (GPT-4) and the Crystal Graph Convolutional Neural Network (CGCNN) to the problem of discovering rare-earth-doped phosphors for solid-state lighting. We used GPT-4 to datamine the chemical formulas and emission wavelengths of 264 Eu2+-doped phosphors from 274 articles. A CGCNN model was trained on the acquired data set, achieving a test R2 of 0.77. Using this model, we predicted the emission wavelengths of over 40 000 inorganic materials. We also used transfer learning to fine-tune a bandgap-predicting CGCNN model for emission wavelength prediction. The workflow requires minimal human supervision and is generalizable to other fields.

6.
Sci Adv ; 9(30): eadh1789, 2023 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-37506201

RESUMEN

Fast and high-resolution x-ray imaging demands scintillator films with negligible afterglow, high scintillation yield, and minimized cross-talk. However, grain boundaries (GBs) are abundant in polycrystalline scintillator film, and, for current inorganic scintillators, detrimental dangling bonds at GBs inevitably extend radioluminescence lifetime and increase nonradiative recombination loss, deteriorating afterglow and scintillation yield. Here, we demonstrate that scintillators with one-dimensional (1D) crystal structure, Cs5Cu3Cl6I2 explored here, possess benign GBs without dangling bonds, yielding nearly identical afterglow and scintillation yield for single crystals and polycrystalline films. Because of its 1D crystal structure, Cs5Cu3Cl6I2 films with desired columnar morphology are easily obtained via close space sublimation, exhibit negligible afterglow (0.1% at 10 ms) and high scintillation yield (1.2 times of CsI:Tl). We have also demonstrated fast x-ray imaging with 27 line pairs mm-1 resolution and frame rate up to 33 fps, surpassing most existing scintillators. We believe that the 1D scintillators can greatly boost x-ray imaging performance.

7.
Sci Adv ; 9(27): eadg7919, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37406131

RESUMEN

GeTe-based materials with superior thermoelectric properties promise great potential for waste heat recovery. However, the lack of appropriate diffusion barrier materials (DBMs) limits not only the energy conversion efficiency but also the service reliability of the thermoelectric devices. Here, we propose a design strategy based on phase equilibria diagrams from first-principles calculations and identify transition metal germanides (e.g., NiGe and FeGe2) as the DBMs. Our validation experiment confirms the excellent chemical and mechanical stabilities of the interfaces between the germanides and GeTe. We also develop a process for scaling up the GeTe production. Combining with module geometry optimization, we fabricate an eight-pair module using mass-produced p-type Ge0.89Cu0.06Sb0.08Te and n-type Yb0.3Co4Sb12 and achieve a record-high efficiency of 12% among all reported single-stage thermoelectric modules. Our work thus paves the way for waste heat recovery based on completely lead-free thermoelectric technology.

8.
J Chem Phys ; 158(24)2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37358218

RESUMEN

Silver sulfide in monoclinic phase (α-Ag2S) has attracted significant attention owing to its metal-like ductility and promising thermoelectric properties near room temperature. However, first-principles studies on this material by density functional theory calculations have been challenging as both the symmetry and atomic structure of α-Ag2S predicted from such calculations are inconsistent with experimental findings. Here, we propose that a dynamical approach is imperative for correctly describing the structure of α-Ag2S. The approach is based on a combination of ab initio molecular dynamics simulation and deliberately chosen density functional considering both proper treatment of the van der Waals interaction and on-site Coulomb interaction. The obtained lattice parameters and atomic site occupations of α-Ag2S are in good agreement with experimental data. A stable phonon spectrum at room temperature can be obtained from this structure, which also yields a bandgap in accord with experimental measurements. The dynamical approach thus paves the way for studying this important ductile semiconductor in not only thermoelectric but also optoelectronic applications.

9.
Small ; 19(42): e2302935, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37322314

RESUMEN

Organic-inorganic hybrid materials often face a stability challenge. ß-ZnTe(en)0.5 , which uniquely has over 15-year real-time degradation data, is taken as a prototype structure to demonstrate an accelerated thermal aging method for assessing the intrinsic and ambient-condition long-term stability of hybrid materials. Micro-Raman spectroscopy is used to investigate the thermal degradation of ß-ZnTe(en)0.5 in a protected condition and in air by monitoring the temperature dependences of the intrinsic and degradation-product Raman modes. First, to understand the intrinsic degradation mechanism, the transition state of the degradation is identified, then using a density functional theory, the intrinsic energy barrier between the transition state and ground state is calculated to be 1.70 eV, in excellent agreement with the measured thermal degradation barrier of 1.62 eV in N2 environment. Second, for the ambient-condition degradation, a reduced thermal activation barrier of 0.92 eV is obtained due to oxidation, corresponding to a projected ambient half-life of 40 years at room temperature, in general agreement with the experimental observation of no apparent degradation over 15 years. Furthermore, the study reveals a mechanism, conformation distortion enhanced stability, which plays a pivotal role in forming the high kinetic barrier, contributing greatly to the impressive long-term stability of ß-ZnTe(en)0.5 .

10.
Antioxidants (Basel) ; 12(1)2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36670986

RESUMEN

To determine the anti-heat stress and antioxidant effects of genistein and the underlying mechanisms, lipofuscin, reactive oxygen species (ROS), and survival under stress were first detected in Caenorhabditis elegans (C. elegans); then the localization and quantification of the fluorescent protein was determined by detecting the fluorescently labeled protein mutant strain; in addition, the aging-related mRNAs were detected by applying real-time fluorescent quantitative PCR in C. elegans. The results indicate that genistein substantially extended the lifespan of C. elegans under oxidative stress and heat conditions; and remarkably reduced the accumulation of lipofuscin in C. elegans under hydrogen peroxide (H2O2) and 35 °C stress conditions; in addition, it reduced the generation of ROS caused by H2O2 and upregulated the expression of daf-16, ctl-1, hsf-1, hsp-16.2, sip-1, sek-1, pmk-1, and eat-2, whereas it downregulated the expression of age-1 and daf-2 in C. elegans; similarly, it upregulated the expression of daf-16, sod-3, ctl-1, hsf-1, hsp-16.2, sip-1, sek-1, pmk-1, jnk-1 skn-1, and eat-2, whereas it downregulated the expression of age-1, daf-2, gst-4, and hsp-12.6 in C. elegans at 35 °C; moreover, it increased the accumulation of HSP-16.2 and SKN-1 proteins in nematodes under 35 °C and H2O2 conditions; however, it failed to prolong the survival time in the deleted mutant MQ130 nematodes under 35 °C and H2O2 conditions. These results suggest that genistein promote anti-heat stress and antioxidant effects in C. elegans via insulin/-insulin-like growth factor signaling (IIS), heat shock protein (HSP), mitogen-activated protein kinase (MAPK), dietary restriction (DR), and mitochondrial pathways.

11.
Int J Mol Sci ; 23(21)2022 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-36361834

RESUMEN

In this study, we developed a sustained-release transdermal delivery system containing losartan potassium (LP) and verapamil hydrochloride (VPH). LP and VPH have low bioavailability and long half-life. Therefore, the development of an optimum administration mode is necessary to overcome these drawbacks and enhance the antihypertensive effect. A transdermal diffusion meter was used to determine the optimal formulation of LP-VPH transdermal drug delivery systems (TDDS). Based on in vitro results, a sustained-release patch was prepared. Physical characteristics, including quality, stickiness, and appearance, were evaluated in vitro, while pharmacokinetics and skin irritation were evaluated in vivo. The results showed that 8.3% polyvinyl alcohol, 74.7% polyvinylpyrrolidone K30, 12% oleic acid-azone, and 5% polyacrylic acid resin II provided an optimized TDDS product for effective administration of LP and VPH. Furthermore, in vitro and in vivo release tests showed that the system continuously released LP and VPH for 24 h. The pharmacokinetic results indicated that although the maximum concentration was lower, both the area under the curve from 0-time and the mean residence time of the prepared patch were significantly higher than those of the oral preparations. Furthermore, the prepared LP-VPH transdermal patch showed good stability and no skin irritation. The developed LP-VPH TDDS showed a sustained-release effect and good characteristics and pharmacokinetics; therefore, it is an ideal formulation.


Asunto(s)
Losartán , Verapamilo , Preparaciones de Acción Retardada/farmacocinética , Absorción Cutánea , Administración Cutánea , Sistemas de Liberación de Medicamentos/métodos
12.
ACS Nano ; 16(12): 21079-21086, 2022 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-36383161

RESUMEN

The kagome lattice has attracted intense interest with the promise of realizing topological phases built from strongly interacting electrons. However, fabricating two-dimensional (2D) kagome materials with nontrivial topology is still a key challenge. Here, we report the growth of single-layer iron germanide kagome nanoflakes by molecular beam epitaxy. Using scanning tunneling microscopy/spectroscopy, we unravel the real-space electronic localization of the kagome flat bands. First-principles calculations demonstrate the topological band inversion, suggesting the topological nature of the experimentally observed edge mode. Apart from the intrinsic topological states that potentially host chiral edge modes, the realization of kagome materials in the 2D limit also holds promise for future studies of geometric frustration.

13.
Nature ; 607(7919): 480-485, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35859196

RESUMEN

Pyroelectricity describes the generation of electricity by temporal temperature change in polar materials1-3. When free-standing pyroelectric materials approach the 2D crystalline limit, how pyroelectricity behaves remained largely unknown. Here, using three model pyroelectric materials whose bonding characters along the out-of-plane direction vary from van der Waals (In2Se3), quasi-van der Waals (CsBiNb2O7) to ionic/covalent (ZnO), we experimentally show the dimensionality effect on pyroelectricity and the relation between lattice dynamics and pyroelectricity. We find that, for all three materials, when the thickness of free-standing sheets becomes small, their pyroelectric coefficients increase rapidly. We show that the material with chemical bonds along the out-of-plane direction exhibits the greatest dimensionality effect. Experimental observations evidence the possible influence of changed phonon dynamics in crystals with reduced thickness on their pyroelectricity. Our findings should stimulate fundamental study on pyroelectricity in ultra-thin materials and inspire technological development for potential pyroelectric applications in thermal imaging and energy harvesting.

14.
Chemistry ; 28(32): e202200234, 2022 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-35357741

RESUMEN

In recent years all-solid-state sodium-ion batteries (SS-SIBs) have drawn significant attention due to their potential to be safer and lower cost than lithium-ion batteries. However, the lack of sodium solid-state electrolytes with high ionic conductivity has become one of the major challenges. Here, with first-principles computation we took NaCuZrS3 , consisting of earth-abundant and environmentally benign elements only, as an example to study Na-ion transport in the post-perovskite-like structure and used computation-guided design to improve its potential as a solid-state electrolyte. With ab initio molecular dynamics simulation and nudged elastic band calculation, we studied possible diffusion mechanisms in this material and found that Na ion interstitials have a favorable migration barrier of 0.22 eV, which is among the smallest in the literature reported values. Considering the large formation energy of Frenkel defects, we proposed doping strategy to introduce extra Na interstitials in the material. Our study suggests that the post-perovskite-like sulfides are worth of exploration for applications in SS-SIBs.

15.
ACS Appl Mater Interfaces ; 14(12): 14157-14164, 2022 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-35302349

RESUMEN

Low-dimensional organic-metal halides are regarded as an emerging class of X-ray scintillation materials, but most of the discovered compounds are confronted with challenges of toxicity and instability. To address these challenges, we herein report two lead-free zero-dimensional (0D) hybrid halides, (Bmpip)2Cu2Br4 and PPh4CuBr2 single crystals, grown by the low-cost solution-processing method. By single-crystal X-ray diffraction refinement, the crystal structures of (Bmpip)2Cu2Br4 and PPh4CuBr2 were determined to be orthorhombic and monoclinic crystal systems, respectively. (Bmpip)2Cu2Br4 and PPh4CuBr2 show broadband orange and yellow emissions peaking at 620 and 538 nm, respectively. Different from the emission nature of the recent reported Cu-based halide hybrids, both (Bmpip)2Cu2Br4 and PPh4CuBr2 emit from excitons bound to defects featuring spin-allowed transition, enabling them to possess fast scintillation decay time of tens of nanoseconds, respectively. In particular, the (Bmpip)2Cu2Br4 single crystal has a high photoluminescence quantum yield of 48.2%, a high scintillation yield of 16,000 photons/MeV, and a low detection limit of 710 nGyair/s. Due to the combination of nontoxicity, long-term stability, and decent detection performance, (Bmpip)2Cu2Br4 could be regarded as a promising X-ray scintillator.

16.
JACS Au ; 1(8): 1208-1216, 2021 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-34467359

RESUMEN

Hard carbons (HCs) as an anode material in sodium ion batteries present enhanced electrochemical performances in ether-based electrolytes, giving them potential for use in practical applications. However, the underlying mechanism behind the excellent performances is still in question. Here, ex situ nuclear magnetic resonance, gas chromatography-mass spectrometry, and high-resolution transmission electron microscopy were used to clarify the insightful chemistry of ether- and ester-based electrolytes in terms of the solid-electrolyte interphase (SEI) on hard carbons. The results confirm the marked electrolyte decomposition and the formation of a SEI film in EC/DEC but no SEI film in the case of diglyme. In situ electrochemical quartz crystal microbalance and molecular dynamics support that ether molecules have likely been co-intercalated into hard carbons. To our knowledge, these results are reported for the first time. It might be very useful for the rational design of advanced electrode materials based on HCs in the future.

17.
J Phys Chem Lett ; 12(34): 8194-8202, 2021 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-34415168

RESUMEN

The development of functional materials calls for ever-enriching the inorganic material database. Doping is an effective way of achieving this purpose. Herein, we propose the concept of dilute element compounds (DECs), which contain a small amount of a dopant element distributed in a host crystal structure in an ordered manner. Different from dilute alloys or solid solutions, the DECs could be more resistant to segregation and are ideal for dispersing functional elements for applications such as single-atom catalysts. It is also expected that the DECs will serve as a route to discovering new inorganic functional materials by controlling phase transitions and tuning intrinsic properties of the host materials with applications including, but not limited to, thermoelectrics and solid-state electrolytes for secondary batteries. As an initial work, we quantify the diluteness of DECs and find the limits of diluteness in existing DECs. We further provide a classification scheme for the DECs to guide future discoveries.

18.
J Biomed Mater Res A ; 109(11): 2294-2305, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33942484

RESUMEN

We aimed to establish a 1-Deoxynojirimycin (DNJ) sustained-release delivery system to improve the hypoglycemic effect of DNJ. We used a transdermal diffusion meter in an in vitro orthogonal experiment to determine the optimal composition of the DNJ sustained-release transdermal system. Based on the in vitro analysis results, a sustained-release patch was prepared, and its pharmacokinetics and other properties were determined in vivo. The results showed that 30% hydroxypropyl methylcellulose (K100M ), 14% carboxymethyl cellulose sodium and 26% oleic acid-azone compound as the matrix material, drug excipient, and penetration enhancer, respectively, produced an optimal DNJ sustained-release delivery system. In vitro release tests showed that the system slowly released DNJ within 12 hr, conforming to the Higuchi equation. In vivo experiments showed that the prepared patch had good hypoglycemic activity and continuously released DNJ within 10 hr. In vivo pharmacokinetic study results showed that compared to conventional patches, the prepared patch exhibited significantly different maximum concentration (Cmax ), time to achieve Cmax (Tmax ), and area under the curve from 0 to time t (AUC[0-t] ) as well as improved pharmacokinetics. In conclusion, the prepared DNJ patch has high stability, a sustained-release effect, and relatively good pharmacokinetics and is a safe dosage form that does not cause skin irritation.


Asunto(s)
1-Desoxinojirimicina , Piel/metabolismo , Parche Transdérmico , 1-Desoxinojirimicina/química , 1-Desoxinojirimicina/farmacocinética , 1-Desoxinojirimicina/farmacología , Animales , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacocinética , Preparaciones de Acción Retardada/farmacología , Masculino , Ratones , Conejos
19.
ACS Nano ; 15(6): 10565-10576, 2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34038098

RESUMEN

Organic-inorganic hybrids may offer material properties not available from their inorganic components. However, they are typically less stable and disordered. Long-term stability study of the hybrid materials, over the anticipated lifespan of a real-world electronic device, is practically nonexistent. Disordering, prevalent in most nanostructure assemblies, is a prominent adversary to quantum coherence. A family of perfectly ordered II-VI-based hybrid nanostructures has been shown to possess many unusual properties and potential applications. Here, using a prototype structure ß-ZnTe(en)0.5-a hybrid superlattice-and applying an array of optical, structural, surface, thermal, and electrical characterization techniques, in conjunction with density-functional theory calculations, we have performed a comprehensive and correlative study of the crystalline quality, structural degradation, electronic, optical, and transport properties on samples from over 15 years old to the recently synthesized. The findings show that not only do they exhibit an exceptionally high level of crystallinity in both macroscopic and microscopic scale, comparable to high-quality binary semiconductors; and greatly enhanced material properties, compared to those of the inorganic constituents; but also, some of them over 15 years old remain as good in structure and property as freshly made ones. This study reveals (1) what level of structural perfectness is achievable in a complex organic-inorganic hybrid structure or a man-made superlattice, suggesting a nontraditional strategy to make periodically stacked heterostructures with abrupt interfaces; and (2) how the stability of a hybrid material is affected differently by its intrinsic attributes, primarily formation energy, and extrinsic factors, such as surface and defects. By correlating the rarely found long-term stability with the calculated relatively large formation energy of ß-ZnTe(en)0.5 and contrasting with the case of hybrid perovskite, this work illustrates that formation energy can serve as an effective screening parameter for the long-term stability potential of hybrid materials. The results of the prototype II-VI hybrid structures will, on one hand, inspire directions for future exploration of the hybrid materials, and, on the other hand, provide metrics for assessing the structural perfectness and long-term stability of the hybrid materials.

20.
Nat Commun ; 12(1): 3021, 2021 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-34021141

RESUMEN

Tuning metal-support interaction has been considered as an effective approach to modulate the electronic structure and catalytic activity of supported metal catalysts. At the atomic level, the understanding of the structure-activity relationship still remains obscure in heterogeneous catalysis, such as the conversion of water (alkaline) or hydronium ions (acid) to hydrogen (hydrogen evolution reaction, HER). Here, we reveal that the fine control over the oxidation states of single-atom Pt catalysts through electronic metal-support interaction significantly modulates the catalytic activities in either acidic or alkaline HER. Combined with detailed spectroscopic and electrochemical characterizations, the structure-activity relationship is established by correlating the acidic/alkaline HER activity with the average oxidation state of single-atom Pt and the Pt-H/Pt-OH interaction. This study sheds light on the atomic-level mechanistic understanding of acidic and alkaline HER, and further provides guidelines for the rational design of high-performance single-atom catalysts.

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