One of the most promising solutions to slow down CO emissions is the use of photocatalysis to produce hydrogen as a clean fuel. However, the efficiency of the photocatalysts is not at the desired level, and they usually need precious metal co-catalysts for reactions. In this study, to achieve efficient photocatalytic hydrogen production, a high-entropy oxide was synthesized by a mechano-thermal method. The synthesized high-entropy oxide had a bandgap of 2.45 eV, which coincided with both UV and visible light regions. The material could successfully produce hydrogen from water under light, but the main difference to conventional photocatalysts was that the photocatalysis proceeded without a co-catalyst addition. Hydrogen production increased with increasing time, and at the end of the 3 h period, 134.76 µmol/m h of hydrogen was produced. These findings not only introduce a new method for producing high-entropy photocatalysts but also confirm the high potential of high-entropy photocatalysts for hydrogen production without the need for precious metal co-catalysts.
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http://dx.doi.org/10.3390/ma17040853 | DOI Listing |
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January 2025
Department of Chemistry (BK21 FOUR), Research Institute of Natural Sciences, Gyeongsang National University, Jinju, 52828, Republic of Korea.
Herein, multi-walled carbon nanotubes (CNT) embedded with RuPdIrPtAu-high entropy alloys (HEA) via pulsed laser irradiation in liquids are successfully fabricated. The resultant composite synergistically enhances hydrazine oxidation reaction (HzOR)-boosted water electrolysis. Notably, HEA with ≈2-5 nm size, are uniformly distributed across the surface of the CNTs.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
As a leading candidate for high-voltage, cobalt-free cathodes, spinel LiNiMnO (LNMO) oxide is highly attractive for next-generation lithium-ion batteries. However, the instability of cation-oxygen bonds (especially Mn-O) and the adverse two-phase transition of LNMO result in rapid crystal collapse during cycling, thus limiting its practical deployment. To address these issues, herein we exploit the differences in miscibility between dopants and the spinel matrix to embed high-entropy doped microregions (HEDRs, 5-15 nm in size) within the spinel.
View Article and Find Full Text PDFNat Commun
January 2025
School of Chemical Engineering, The University of Adelaide, Adelaide, SA, Australia.
High-entropy alloy nanoparticles (HEA-NPs) exhibit favorable properties in catalytic processes, as their multi-metallic sites ensure both high intrinsic activity and atomic efficiency. However, controlled synthesis of uniform multi-metallic ensembles at the atomic level remains challenging. This study successfully loads HEA-NPs onto a nitrogen-doped carbon carrier (HEAs) and pioneers the application in peroxymonosulfate (PMS) activation to drive Fenton-like oxidation.
View Article and Find Full Text PDFNanoscale
January 2025
J. Heyrovský Institute of Physical Chemistry, Czech Acad. Sci., Dolejškova 3, CZ-18200, Prague 8, Czech Republic.
Compositionally complex doping of spinel oxides toward high-entropy oxides is expected to enhance their electrochemical performance substantially. We successfully prepared high-entropy compounds, the oxide (ZnMgCoCu)FeO (HEOFe), lithiated oxyfluoride Li(ZnMgCoCu)FeOF (LiHEOFeF), and lithiated oxychloride Li(ZnMgCoCu)FeOCl (LiHEOFeCl) with a spinel-based cubic structure by ball milling and subsequent heat treatment. The products exhibit particles with sizes from 50 to 200 nm with a homogeneous atomic distribution.
View Article and Find Full Text PDFAdv Mater
January 2025
School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, China.
Understanding the behavior of high-entropy carbides (HECs) under oxygen-containing environments is of particular importance for their promising applications in structural components, catalysis, and energy-related fields. Herein, the structural evolution of (Ta, Ti, Cr, Nb)C (HEC-1) nanoparticles (NPs) is tracked in situ during the oxidation at the atomic scale by using an open-cell environmental aberration-corrected scanning transmission electron microscope. Three key stages are clearly discerned during the oxidation of HEC-1 NPs at the atomic level below 900 °C: i) increased amorphization of HEC-1 NPs from 300 to 500 °C due to the energetically favorable formation of carbon vacancies and substitution of carbon with oxygen atoms; ii) nucleation and subsequent growth of locally ordered nanocluster intermediates within the generated amorphous oxides from 500 to 800 °C; and iii) final one-step crystallization of non-equimolar MeO and MeO (Me = metallic elements, Ta, Ti, Cr, and Nb) high-entropy oxides above 800 °C, accompanied with the reduction in atomic defects.
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