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1.
Nanoscale ; 15(8): 3919-3930, 2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36723258

RESUMO

In catalyzed electrochemical reactions, a general strategy is to modify electrode materials to increase the efficiency of the reaction. From the viewpoint of environmental protection, electrochemical reactions should be performed in an inert green water phase. In this study, we report active pure liquid water (named PV), which was collected from the condensed vapor of heated gold (Au)-containing plasmon-activated water (PAW) with a distinct structure of electron-doping and reduced hydrogen bonding (HB). The resulting PV also exhibited distinct properties of the formation of stronger intermolecular HB with alcohols, and notable activities in catalytic electrochemical reactions, compared to bulk deionized water (DIW). Moreover, the measured diffusion coefficients of water increased by ca. 30% in PV solutions. Two typical electrochemical reactions significantly increased peak currents observed in oxidation-reduction cycles (ORCs) with roughening of the Au substrate and in a model of reversible oxidation-reduction reactions on a platinum (Pt) substrate. Also, PV enhanced hydrogen evolution reactions (HERs) on catalytic Pt and inert stainless steel substrates in PV-based solutions at different pH values, compared to DIW. Moreover, these activities of PV were more marked, even better than those of PAW, when PV was collected under a higher heating rate used to heat PAW. Active pure PV has emerged as a promising green solvent applicable to various chemical reactions with more efficiency.

2.
ACS Omega ; 4(25): 21197-21203, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31867513

RESUMO

The innovative plasmon-activated water (PAW) with reduced hydrogen bonds exhibits intrinsically distinct properties at room temperature, which are significantly different from the properties of untreated conventional deionized (DI) water. Examples of this are their ability to scavenge free radicals and higher vapor pressure. However, distinct properties of energetic PAW decay within the day after its creation in a metastable liquid state. In this work, we report a facile method for persisting its distinct activities by letting as-prepared PAW be quickly frozen in liquid nitrogen and letting the frozen PAW (for one month before further measurements) be quickly melted to room temperature in a warm-water bath (called treated PAW). Experimental results indicate that the activity of the higher evaporation rate of treated PAW compared to DI water can be maintained ca. 90% of magnitude, as compared to the as-prepared PAW. Also, its abilities to scavenge free hydroxyl and 2,2-diphenyl-1-picrylhydrazyl radicals can be maintained at ca. 70 and 80% of magnitudes, respectively. Moreover, this strategy of quickly freezing and melting treatments to PAW on persisting in distinct activity of PAW is effective in oxygen evolution reactions. This promises the stored energy and the distinct property of created liquid PAW being available in water-related fields after long-term storage.

3.
Sci Rep ; 9(1): 10398, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31320695

RESUMO

Due to increasing global warming resulting from the greenhouse effect, subsequent environmental impacts and corresponding ecological influences are unavoidable. These problems are becoming more serious with time. Due to rising temperatures, the survival crisis of polar bears is a very often reported issue, because polar bears are encountering shortened seasons for catching prey on their sea-ice habitat. In this work, we report an innovative and facile strategy to save polar bears via prolonging the existence of ice layers based on plasmon-activated water (PAW). PAW with a reduced hydrogen-bonded network can be created by letting bulk deionized (DI) water flow through supported gold nanoparticles (AuNPs) under resonant illumination. Experimental results indicated that the freezing time of PAW was faster than that of DI water. In contrast, the melting time of frozen PAW was slower than that of the frozen DI water. Because the PAW with reduced hydrogen bonds (HBs) is in a high-energy state, it can more easily transform into a stronger HB structure in a low-energy state during cooling when freezing. This is accompanied by the release of more available energy, resulting in more-perfect tetrahedral symmetrical ice. Similar results were observed for solutions with 3 wt% NaCl, which is similar to the salinity of sea water. Moreover, the heat required to melt frozen PAW was ca. 7.6% higher than that of frozen DI water. These interesting phenomena suggest that prolonging the existence of solid ice can be achieved in a PAW-based system. Moreover, a system of AuNP-coated filter paper in DI water or in a DI water solution (3 wt% NaCl) under resonant illumination could work to prolong the presence of solid ice, compared to a system of AuNP-free filter paper. This innovative concept has emerged as a practical strategy to save polar bears and for other related applications.


Assuntos
Camada de Gelo/química , Água do Mar/química , Ursidae/fisiologia , Água/química , Animais , Mudança Climática , Ecossistema , Aquecimento Global , Ouro/química , Efeito Estufa , Ligação de Hidrogênio , Nanopartículas Metálicas/química , Estações do Ano , Temperatura
4.
ACS Omega ; 3(5): 4743-4751, 2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31458693

RESUMO

Conventionally, reactions in aqueous solutions are prepared using deionized (DI) water, the properties of which are related to inert "bulk water" comprising a tetrahedral hydrogen-bonded network. In this work, we demonstrate the distinguished benefits of using in situ plasmon-activated water (PAW) with reduced hydrogen bonds instead of DI water in electrochemical reactions, which generally are governed by diffusion and kinetic controls. Compared with DI water-based systems, the diffusion coefficient and the electron-transfer rate constant of K3Fe(CN)6 in PAW in situ can be increased by ca. 35 and 15%, respectively. These advantages are responsible for the improved performance of surface-enhanced Raman scattering (SERS). On the basis of PAW in situ, the SERS enhancement of twofold higher intensity of rhodamine 6G and the corresponding low relative standard deviation of 5%, which is comparable to and even better than those based on complicated processes shown in the literature, are encouraging.

5.
Sci Rep ; 6: 22166, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26916099

RESUMO

The strength of hydrogen bond (HB) decides water's property and activity. Here we propose the mechanisms on creation and persistence of innovatively prepared liquid water, which is treated by Au nanoparticles (AuNPs) under resonant illumination of green-light emitting diode (LED) to create Au NP-treated (sAuNT) water, with weak HB at room temperature. Hot electron transfer on resonantly illuminated AuNPs, which is confirmed from Au LIII-edge X-ray absorption near edge structure (XANES) spectra, is responsible for the creation of negatively charged sAuNT water with the incorporated energy-reduced hot electron. This unique electronic feature makes it stable at least for one week. Compared to deionized (DI) water, the resulting sAuNT water exhibits many distinct properties at room temperature. Examples are its higher activity revealed from its higher vapor pressure and lower specific heat. Furthermore, Mpemba effect can be successfully explained by our purposed hypothesis based on sAuNT water-derived idea of water energy and HB.

6.
Sci Rep ; 5: 16263, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26541371

RESUMO

Splitting water for hydrogen production using light, or electrical energy, is the most developed 'green technique'. For increasing efficiency in hydrogen production, currently, the most exciting and thriving strategies are focused on efficient and inexpensive catalysts. Here, we report an innovative idea for efficient hydrogen evolution reaction (HER) utilizing plasmon-activated liquid water with reduced hydrogen-bonded structure by hot electron transfer. This strategy is effective for all HERs in acidic, basic and neutral systems, photocatalytic system with a g-C3N4 (graphite carbon nitride) electrode, as well as in an inert system with an ITO (indium tin oxide) electrode. Compared to deionized water, the efficiency of HER increases by 48% based on activated water ex situ on a Pt electrode. Increase in energy efficiency from activated water is 18% at a specific current yield of -20 mA in situ on a nanoscale-granulated Au electrode. Moreover, the onset potential of -0.023 V vs RHE was very close to the thermodynamic potential of the HER (0 V). The measured current density at the corresponding overpotential for HER in an acidic system was higher than any data previously reported in the literature. This approach establishes a new vista in clean green energy production.

7.
Sci Rep ; 4: 4425, 2014 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-24651843

RESUMO

Uremic toxins are mainly represented by blood urine nitrogen (BUN) and creatinine (Crea) whose removal is critically important in hemodialysis (HD) for kidney disease. Patients undergoing HD have a complex illness, resulting from: inadequate removal of organic waste, dialysis-induced oxidative stress and membrane-induced inflammation. Here we report innovative breakthroughs for efficient and safe HD by using a plasmon-induced dialysate comprising Au nanoparticles (NPs)-treated (AuNT) water that is distinguishable from conventional deionized (DI) water. The diffusion coefficient of K3Fe(CN)6 in saline solution can be significantly increased from 2.76, to 4.62 × 10(-6) cm s(-1), by using AuNT water prepared under illumination by green light-emitting diodes (LED). In vitro HD experiments suggest that the treatment times for the removals of 70% BUN and Crea are reduced by 47 and 59%, respectively, using AuNT water instead of DI water in dialysate, while additionally suppressing NO release from lipopolysaccharide (LPS)-induced inflammatory cells.


Assuntos
Ouro/farmacologia , Soluções para Hemodiálise/química , Nanopartículas Metálicas/química , Diálise Renal/métodos , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Creatinina/isolamento & purificação , Ferricianetos/química , Ouro/química , Soluções para Hemodiálise/efeitos da radiação , Humanos , Luz , Lipopolissacarídeos/antagonistas & inibidores , Óxido Nítrico/antagonistas & inibidores , Estresse Oxidativo , Segurança do Paciente , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/terapia , Análise Espectral Raman , Resultado do Tratamento
8.
ACS Nano ; 8(3): 2704-13, 2014 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-24533852

RESUMO

The properties of confined liquid water, or liquid water in contact with hydrophobic surfaces, are significantly different from those of bulk liquid water. However, all of water's commonly described properties are related to inert "bulk liquid water" which comprises a tetrahedral hydrogen-bonded network. In this work, we report an innovative and facile method for preparing small water clusters (SWCs) with reduced affinity hydrogen bonds by letting bulk water flow through supported Au nanoparticles (NPs) under resonant illumination to give NP-treated (AuNT) water at constant temperature. Utilizing localized surface plasmon resonance on illuminated Au NPs, the strong hydrogen bonds of bulk water can be disordered when water is located at the illuminated Au/water interface. The prepared SWCs are free of Au NPs. The energy efficiency for creating SWCs is ∼17%. The resulting stable AuNT water exhibits distinct properties at room temperature, which are significantly different from the properties of untreated bulk water, examples being their ability to scavenge free hydroxyl and 2,2-diphenyl-1-picrylhydrazyl radicals and to effectively reduce NO release from lipopolysaccharide-induced inflammatory cells.

9.
Anal Chim Acta ; 806: 188-96, 2014 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-24331055

RESUMO

Because Ag and Au nanoparticles (NPs) possess well-defined localized surface plasmon resonance (LSPR) they are popularly employed in the studies of surface-enhanced Raman scattering (SERS). As shown in the literature and in our previous studies, the advantage of SERS-active Ag NPs is their higher SERS enhancement over Au NPs. On the other hand, the disadvantage of SERS-active Ag NPs compared to Au NPs is their serious decay of SERS enhancement in ambient laboratory air. In this work, we develop a new strategy for preparing highly SERS-active Ag NPs deposited on a roughened Au substrate. This strategy is derived from the modification of electrochemical underpotential deposition (UPD) of metals. The coverage of Ag NPs on the roughened Au substrate can be as high as 0.95. Experimental results indicate that the SERS of Rhodamine 6G (R6G) observed on this developed substrate exhibits a higher intensity by ca. 50-fold of magnitude, as compared with that of R6G observed on the substrate without the deposition of Ag NPs. The limit of detection (LOD) for R6G measured on this substrate is markedly reduced to 2×10(-15)M. Moreover, aging of SERS effect observed on this developed substrate is significantly depressed, as compared with that observed on a generally prepared SERS-active Ag substrate. These aging tests were performed in an atmosphere of 50% relative humidity (RH) and 20% (v/v) O2 at 30°C for 60 day. Also, the developed SERS-active substrate enables it practically applicable in the trace detection of monosodium urate (MSU)-containing solution in gouty arthritis without a further purification process.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Prata/química , Análise Espectral Raman , Técnicas de Química Analítica , Rodaminas/análise , Propriedades de Superfície
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