Hydrogen adsorption/desorption behavior plays a key role in hydrogen evolution reaction (HER) catalysis. The HER reaction rate is a trade-off between hydrogen adsorption and desorption on the catalyst surface. Herein, we report the rational balancing of hydrogen adsorption/desorption by orbital modulation using introduced environmental electronegative carbon/nitrogen (C/N) atoms. Theoretical calculations reveal that the empty d orbitals of iridium (Ir) sites can be reduced by interactions between the environmental electronegative C/N and Ir atoms. This balances the hydrogen adsorption/desorption around the Ir sites, accelerating the related HER process. Remarkably, by anchoring a small amount of Ir nanoparticles (7.16 wt%) in nitrogenated carbon matrixes, the resulting catalyst exhibits significantly enhanced HER performance. This includs the smallest reported overpotential at 10 mA cm (4.5 mV), the highest mass activity at 10 mV (1.12 A mg) and turnover frequency at 25 mV (4.21 H s) by far, outperforming Ir nanoparticles and commercial Pt/C.
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http://dx.doi.org/10.1038/s41467-019-12012-z | DOI Listing |
Mikrochim Acta
January 2025
School of Public Health, Hebei Key Laboratory of Occupational Health and Safety for Coal Industry, North China University of Science and Technology, No. 21 Bohai Road, Caofeidian, Tangshan, 063210, Hebei, China.
Biochars (BCs) derived from waste-branches of apple tree, grape tree, and oak were developed for direct solid-phase extraction (SPE) of five benzodiazepines (BZDs) in crude urine samples prior to liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination. Scanning electron microscopy, elemental analyzer, X-ray diffractometry, N adsorption/desorption experiments, and Fourier transform infrared spectrometry characterizations revealed the existence of their mesoporous structure and numerous oxygen-containing functional groups. The obtained BCs not only possessed high affinity towards BZDs via π-π and hydrogen bond interactions, but also afforded the great biocompatibility of excluding interfering components from undiluted urine samples when using SPE adsorbents.
View Article and Find Full Text PDFChem Sci
December 2024
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China
The altered solvation structures and dynamical properties of water molecules at the metal/water interfaces will affect the elementary step of an electrochemical process. Simulating the interfacial structure and dynamics with a realistic representation will provide us with a solid foundation to make a connection with experimental studies. To surmount the accuracy-efficiency tradeoff and provide dynamical insights, we use state-of-the-art machine learning molecular dynamics (MLMD) to study the water exchange dynamics, which are fundamental to adsorption/desorption and electrochemical reaction steps.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Inorganic Chemical Technology and Environment Engineering, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology in Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland.
The photocatalytic reduction of CO to useful products is an area of active research because it shows a potential to be an efficient tool for mitigating climate change. This work investigated the modification of titania with copper(II) nitrate and its impact on improving the CO reduction efficiency in a gas-phase batch photoreactor under UV-Vis irradiation. The investigated photocatalysts were prepared by treating P25-copper(II) nitrate suspensions (with various Cu concentrations), alkalized with ammonia water, in a microwave-assisted solvothermal reactor.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China. Electronic address:
Developing efficient and cost-effective rare earth element-based electrocatalysts for water splitting remains a significant challenge. To address this, interface engineering and charge modulation strategies were employed to create a three-dimensional coral-like CeF/MoO heterostructure electrocatalyst, grown in situ on the multistage porous channels of carbonized sugarcane fiber (CSF). Integrating abundant CeF/MoO heterostructure interfaces and numerous oxygen vacancy defects significantly enhanced the catalyst's active sites and molecular activation capabilities.
View Article and Find Full Text PDFBiosens Bioelectron
December 2024
School of Pharmacy, Xi'an Medical University, Xi'an, 710021, China; Institute of Medicine, Xi'an Medical University, Xi'an, 710021, China. Electronic address:
In this study, a convenient method was proposed for the synthesis of thymine-capped mesoporous silica nanoparticles (MSN) using strong hydrogen bonding in non-protonic solvent. Furthermore, application of the functionalized MSN for the recognition of mercuric ion (Hg) based on a paper-based platform with smartphone-assisted colorimetric detection was developed. The synthesized materials were characterized by techniques including X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FTIR), N adsorption-desorption, particle size analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA).
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