We reveal a unique mechanism by which pure water can be dissociated to form free radicals without requiring catalysts, electrolytes, or electrode contact by means of high-frequency nanometer-amplitude electromechanical surface vibrations in the form of surface acoustic waves (SAWs) generated on a piezoelectric substrate. The physical undulations associated with these mechanical waves, in concert with the evanescent electric field arising from the piezoelectric coupling, constitute half-wavelength "nanoelectrochemical cells" in which liquid is trapped within the SAW potential minima with vertical dimensions defined by the wave amplitude (∼10 nm), thereby forming highly confined polarized regions with intense electric field strengths that enable the breakdown of water. The ions and free radicals that are generated rapidly electromigrate under the high field intensity in addition to being convectively transported away from the cells by the bulk liquid recirculation generated by the acoustic excitation, thereby overcoming mass transport limitations that lead to ion recombination.
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http://dx.doi.org/10.1021/acs.jpclett.0c01227 | DOI Listing |
Sci Rep
January 2025
Chemical Engineering and Pilot Plant Department, Engineering & Renewable Energy Research Institute, National Research Centre (NRC), Giza, 12622, Egypt.
Humans have contaminated water supplies with harmful compounds, including different heavy metals. Heavy metals can interfere with human and animal vital organs and metabolic processes. They are also persistent and bioaccumulative.
View Article and Find Full Text PDFNat Geosci
December 2024
Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, France.
Saturn's rings have been estimated to be as young as about 100 to 400 million years old according to the hypothesis that non-icy micrometeoroid bombardment acts to darken the rings over time and the Cassini observation indicated that the ring particles appear to be relatively clean. These young age estimates assume that the rings formed out of pure water ice particles with a high accretion efficiency of impacting non-icy micrometeoroid material ( ≳ 10%). Here we show, using numerical simulations of hypervelocity micrometeoroid impacts on a ring particle, that non-icy material may not be as readily accreted as previously thought.
View Article and Find Full Text PDFNat Commun
January 2025
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, P. R. China.
With the rapid development of graphene industry, low-cost sustainable synthesis of monolayer graphene oxide (GO) has become more and more important for many applications such as water desalination, thermal management, energy storage and functional composites. Compared to the conventional chemical oxidation methods, water electrolytic oxidation of graphite-intercalation-compound (GIC) shows significant advantages in environmental-friendliness, safety and efficiency, but suffers from non-uniform oxidation, typically ~50 wt.% yield with ~50% monolayers.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Department of Chemistry and Materials Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan.
Hydride (H) species on oxides have been extensively studied over the past few decades because of their critical role in various catalytic processes. Their syntheses require high temperatures and the presence of hydrogen, which involves complex equipment, high energy costs, and strict safety protocols. Hydride species tend to decompose in the presence of atmospheric oxygen and water, which reduces their catalytic activities.
View Article and Find Full Text PDFSci Total Environ
January 2025
School of the Environment, University of Queensland, QLD, Australia.
The transition to net zero emissions requires the capture of carbon dioxide from industrial point sources, and direct air capture (DAC) from the atmosphere for geological storage. Dissolved CO has reactivity to rock core, and while the majority of previous studies have concentrated on reservoir rock or cap-rock reactivity, the underlying seal formation may also react with CO. Drill core from the underlying seal of a target CO storage site was reacted at in situ conditions with pure CO, and compared with an impure CO stream with SO, NO and O that could be expected from hard to abate industries.
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