Photocatalytic reduction of CO_(2)to chemical fuels enables a sustainable way of reducing carbon emissions but faces a high reduction potential due to the high stability of CO_(2)***,we prepared a SnO_(2)/SnS_(2)/Cu_(...
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Photocatalytic reduction of CO_(2)to chemical fuels enables a sustainable way of reducing carbon emissions but faces a high reduction potential due to the high stability of CO_(2)***,we prepared a SnO_(2)/SnS_(2)/Cu_(2)SnS_(3)double Z-scheme heterojunction photocatalyst,in which SnO_(2),SnS_(2),and Cu_(2)SnS_(3)absorb ultraviolet,visible,and near-infrared light,*** on the comprehensive analysis of in-situ X-ray photoelectron spectroscopy and photo(chemical)characterizations,we find that the photogenerated electrons would transfer from SnO_(2)to SnS_(2)to Cu_(2)SnS_(3).The optimized SnO_(2)/SnS_(2)/Cu_(2)SnS_(3)–0.3 double Z-scheme heterojunction could achieve 28.44μmol g^(–1)h^(–1)ethanol yield and 92%selectivity,which is roughly 3 folds higher than SnO_(2)/SnS_(2)single Z-scheme *** using in-situ diffuse reflectance infrared Fourier-transform spectroscopy,we observe that ethanol is produced through a∗COCOH pathway,in which Cu_(2)SnS_(3)would decrease the activation energy barrier from^(∗)COOH to^(∗)CO.
In this paper a projectile ion-recoil ion coincidence technique is used to investigate the transfer ionization processes in collisions of 0.22-6.30 MeV Cq+ ions and 0.25-6.35 MeV 0q+ ions (q=1, 2, 3, 4) with the H...
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In this paper a projectile ion-recoil ion coincidence technique is used to investigate the transfer ionization processes in collisions of 0.22-6.30 MeV Cq+ ions and 0.25-6.35 MeV 0q+ ions (q=1, 2, 3, 4) with the He atom separately. The cross section ratio f of transfer ionization to single electron transfer is measured, and the dependence of f on both charge state q and energy E of the projectiles is investigated. The electron-structure and the mechanisms leading to transfer ionization affect the dependence of f on q and E. Our measurements, along with other data published previously, suggest a similar dependence of f on charge state and energy of projectile for partially stripped ions over a large energy range. The maximum value of f is approximately 0.17q^0.60; the energy corresponding to maximum f is about 160q^0.60 keV/u.
In this study, a potentially universal new strategy is reported for the large-scale, low-cost fabrication of visible-light-active highly ordered heteronanostructures based on the spontaneous photoelectric-field-enhanc...
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In this study, a potentially universal new strategy is reported for the large-scale, low-cost fabrication of visible-light-active highly ordered heteronanostructures based on the spontaneous photoelectric-field-enhancement effect inherent in pyramidal morphology. The hierarchical vertically oriented arrayed structures comprise an active molecular co-catalyst at the apex of a visible-light-active large band gap semiconductor for low-cost solar water splitting in a neutral aqueous medium without the use of a sacrificial agent.
Solar-driven photocatalytic water/seawater splitting holds great potential for green hydrogen ***,the practical application is hindered by the relatively low conversion efficiency resulting from the inadequate utiliza...
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Solar-driven photocatalytic water/seawater splitting holds great potential for green hydrogen ***,the practical application is hindered by the relatively low conversion efficiency resulting from the inadequate utilization of solar spectrum with significant waste in the form of ***,current equipment struggles to maintain all-day operation subjected to the lack of light during ***,a novel hybrid system integrating photothermal catalytic(PTC)reactor,thermoelectric generator(TEG),and phase change materials(PCM)was proposed and designed(named as PTC-TEG-PCM)to address these challenges and enable simultaneous overall seawater splitting and 24-hour power *** PTC system effectively maintains in an optimal temperature range to maximize photothermal-assisted photocatalytic hydrogen *** TEG component recycles the low-grade waste heat for power generation,complementing the shortcoming of photocatalytic conversion and achieving cascade utilization of full-spectrum solar ***,exceptional thermal storage capability of PCM allow for the conversion of released heat into electricity during nighttime,contributing significantly to the overall power output and enabling PTC-TEG-PCM to operate for more than 12 h under the actual *** to traditional PTC system,the overall energy conversion efficiency of the PTC-TEG-PCM system can be increased by∼500%,while maintaining the solar-to-hydrogen *** advancement of this novel system demonstrated that recycling waste heat from the PTC system and utilizing heat absorption/release capability of PCM for thermoelectric application are effective strategies to improve solar energy *** flexible parameter designing,PTC-TEG-PCM can be applied in various scenarios,offering high efficiency,stability,and sustainability.
Supercritical water gasification is a promising technology for wet biomass *** this paper,Ni and other metal catalysts were synthesized by wet *** stability and catalytic activities of Ni catalysts were ***,catalytic ...
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Supercritical water gasification is a promising technology for wet biomass *** this paper,Ni and other metal catalysts were synthesized by wet *** stability and catalytic activities of Ni catalysts were ***,catalytic activities of Ni,Fe,Cu catalysts supported on MgO were tested using wheat straw as raw material in a batch reactor at 723 K and water density of 0.07 cm^(3)/*** results showed that the order of metal catalyst activity for hydrogen generation was Ni/MgO>Fe/MgO>Cu/***,the influence of different supports on Ni catalysts performance was *** results showed that the order of the Ni catalysts’activity with different supports was Ni/MgO>Ni/ZnO>Ni/Al_(2)O_(3)>Ni/ZrO_(2).Finally,the effects of Ni loading and the amount of Ni catalyst addition on hydrogen production,and the stability of Ni/MgO catalyst were *** was found that serious deactivation of Ni catalyst in the process of supercritical water gasification took *** if carbon deposited on the catalyst surface was removed by high temperature calcination and the catalyst was reduced with hydrogen,the activity of used catalyst was only partially restored.
This paper proposed a new structure of highly-dense micro-jet arrays for hybrid jet-impingement/microchannel heat sinks(~120 jet per cm^(2) with jet width of 0.35 mm).Parametric study is performed to investigate the i...
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This paper proposed a new structure of highly-dense micro-jet arrays for hybrid jet-impingement/microchannel heat sinks(~120 jet per cm^(2) with jet width of 0.35 mm).Parametric study is performed to investigate the influence of structure and flow parameters on the convective heat transfer of water jet cooling in confined *** simulation results show that the optimal jet width,jet spacing and impingement distance are around 0.2 mm,0.2 mm and 0.3 mm,respectively,which can achieve a low thermal resistance as well as a relatively low pressure *** analysis of the heat transfer pathways shows that the micro-fin jet structures can extend the impinging heat transfer area and conduct a considerable proportion of heat,which can reach up to 38.9%with the Reynolds number ranging from 797.1 to *** heat transfer characteristics in the heat sink will shift from impingement dominated heat transfer to the channel-convection dominated heat transfer as the jet impingement distance increases.A correlation is proposed to predict the average Nusselt number on the stagnation area for the heat sink with different structure parameters,and the deviations of predictions from the numerical results are less than 10%.
Achieving a high carrier migration efficiency by constructing built-in electric field is one of the promising approaches for promoting photocatalytic activity. Herein, we have designed a donor-acceptor(D-A) crystallin...
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Achieving a high carrier migration efficiency by constructing built-in electric field is one of the promising approaches for promoting photocatalytic activity. Herein, we have designed a donor-acceptor(D-A) crystalline carbon nitride(APMCN) with 4-amino-2,6-dihydroxypyrimidine(AP) as electron donor, in which the pyrimidine ring was well embedded in the heptazine ring via hydrogen-bonding effect during hydrothermal process. The APMCN shows superior charge-transfer due to giant built-in electric field(5.94times higher than pristine carbon nitride), thereby exhibiting excellent photocatalytic H_(2) evolution rate(1350 μmol/h) with a high AQY(62.8%) at 400 nm. Mechanistic analysis based on detailed experimental investigation together with theoretical analysis reveals that the excellent photocatalytic activity is attributed to the promoted charge separation by the giant internal electric field originated from the D–A structure.
The residual gas and remained raw gas in dual gas resources polygeneration system are quite complex in components(mainly CH_(4),CO,and H_(2)),and these results to the distinguished differences in combustion *** invest...
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The residual gas and remained raw gas in dual gas resources polygeneration system are quite complex in components(mainly CH_(4),CO,and H_(2)),and these results to the distinguished differences in combustion *** investigations on basic combustion characteristics of syngas referred above are conducted on a laboratory-scale combustor with flame temperature and flue gas composition measured and *** air coefficient(PA),total air coefficient(TA),and components of the syngas(CS)are selected as key factors,and it is found that PA dominates mostly the ignition of syngas and NOx formation,while TA affects the flue gas temperature after high temperature region and NOx formation trend to be positive as H_(2)/CO components *** results provide references for industrial utilization.
The paper summarized the work on hydrogen enriched hydrocarbons combustion and its application in engines. The progress and understanding on laminar burning velocity, flame instability, flame structure flame and chemi...
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The paper summarized the work on hydrogen enriched hydrocarbons combustion and its application in engines. The progress and understanding on laminar burning velocity, flame instability, flame structure flame and chemical kinetics were presented. Based on funda- mental combustion, both homogeneous spark-ignition engine and direct-injection spark-ignition engine fueled with natural gas-hydrogen blends were conducted and the technical route of natural gas-hydrogen combined with exhaust gas recirculation was proposed which experimen- tally demonstrated benefits on both thermal efficiency improvement and emissions reduction.
The combustion and emission characteristics of a turbo-charged, common rail diesel engine fuelled with diesel-biodiesel-DEE blends were investigated. The study repons that the brake-specific fuel consumption of diesel...
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The combustion and emission characteristics of a turbo-charged, common rail diesel engine fuelled with diesel-biodiesel-DEE blends were investigated. The study repons that the brake-specific fuel consumption of dieselbiodiesel-DEE blends increases with increase of oxygenated fuel fractions in the blends. Brake thermal efficiency shows little variation when operating on different dieselbiodiesel-DEE blends. At a low load, the NOx emission of the diesel-biodiesel-DEE blends exhibits little variation in comparison with the biodiesel fraction. The NOx emission slightly increases with increase in the biodiesel fraction in diesel-biodiesel-DEE blends at medium load. However,the NOx emission increases remarkably with increase of the biodiesel fraction at high load. Particle mass concentration decreases significantly with increase of the oxygenated-fuels fraction at all engine speeds and loads;particle number concentration decreases remarkably with increase of the oxygenated-fuels fraction. HC and CO emissions decrease with increasing oxygenated-fuels fraction in these blends.
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