Advancing catalyst design is pivotal for the enhancement of photocatalytic processes in renewable energy conversion. The incorporation of structural chirality into conventional inorganic solar hydrogen nanocatalysts p...
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Advancing catalyst design is pivotal for the enhancement of photocatalytic processes in renewable energy conversion. The incorporation of structural chirality into conventional inorganic solar hydrogen nanocatalysts promises a significant transformation in catalysis, a feature absent in this field. Here we unveil the unexplored potential of geometric chirality by creating a chiral composite that integrates geometric chiral Au nanoparticles (NPs) with two-dimensional C 3 N 4 nanosheets, significantly boosting photocatalytic H 2 evolution beyond the achiral counterparts. The superior performance is driven by the geometric chirality of Au NPs, which facilitates efficient charge carrier separation through the favorable C 3 N 4 -chiral Au NP interface and chiral induced spin polarization, and exploits high-activity facets within the concave surfaces of chiral Au NPs. The resulting synergistic effect leads to a remarkable increase in photocatalytic H 2 evolution, with an apparent quantum yield of 44.64 % at 400 nm. Furthermore, we explore the selective polarized photo-induced carrier separation behavior, revealing a distinct chiral-dependent photocatalytic HER performance. Our work advances the design and utilization of chiral inorganic nanostructures for superior performance in energy conversion processes.
The use of carbon nitride-based materials and light to drive catalytic water splitting has enormous potential for the production of hydrogen. Revealing the processes of molecular conjugation, nucleation, and crystalli...
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To enhance knowledge about efficiency improvement and reactor optimization in supercritical water gasification,an experimental system was designed to study the pressure and temperature distribution of subcritical and ...
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To enhance knowledge about efficiency improvement and reactor optimization in supercritical water gasification,an experimental system was designed to study the pressure and temperature distribution of subcritical and supercritical water in a channel,representing a simplified continuous *** pressure drop and temperature distribution along and perpendicular to the forced flow are studied by the measure points inserted inside the test *** results show that the pressure drop in the test section is linearly negatively correlated with the average enthalpy of the inlet and outlet,eventually reaching negative values(-0.177 MPa)at high average enthalpy(2300 kJ kg^(-1)).Temperature and specific enthalpy along the flow direction match theoretical estimates,except near the pseudocritical *** subcritical cases,horizontal temperature differences are positively correlated with enthalpy differences and mass flow rates but remain nearly constant in supercritical ***,with fluid temperature rising from the pseudocritical point,the horizontal temperature difference first increases,then decreases,and reaching a peak of 4.29 K at a fluid temperature of 664 *** of the obtained data reveals that the negative correlation and values of the pressure drop are caused by fluid volume ***,fluid volume expansion,near-wall natural convection,and turbulent forced flow fluctuations contribute to horizontal temperature non-uniformity.
Organic Rankine cycle (ORC) which recovers waste heat in the temperature range of 80°C-140°C was investigated. Exergy efficiencies of various components and ORC system were paid great attention. The working ...
Organic Rankine cycle (ORC) which recovers waste heat in the temperature range of 80°C-140°C was investigated. Exergy efficiencies of various components and ORC system were paid great attention. The working fluids of R245fa and R600a are used. It is found that, for saturated ORCs, the expander inlet temperature has the optimum value, so the system exergy efficiency is maximum. With the increase of heat source temperature, the optimal inlet temperature of the expander is also increased. And also for saturated ORCs, the exergy efficiencies of evaporator and expander are highest efficiency, when evaporator exergy efficiency is increased with increase of heat source temperatures, the expander exergy efficiency is unchanged. The condenser decreased exergy efficiencies by increasing the heat source temperatures.
This research focuses on the preparation and properties of rice hull ash(RHA). We prepared RHA from combustion of rice husk in the fluidized-bed reactor. The temperature field of the furnace was steady and bellow 850&...
This research focuses on the preparation and properties of rice hull ash(RHA). We prepared RHA from combustion of rice husk in the fluidized-bed reactor. The temperature field of the furnace was steady and bellow 850°C to keep SiO2 amorphous. XRD, BET and SEM were applied in the characterization tests to investigate the effect of flow rate(u), the higher primary-secondary wind ratio(i) and relative height of bed material. The optimal combustion condition for preparing RHA was discussed. RHA obtained from rice hull contains abundant amorphous SiO2 (>90%) and the characterization results of RHA show its potential to be a good catalyst supporter.
Although aqueous synthesis of nanocrystals is advantageous in terms of the cost, convenience, environmental friendliness, and surface cleanness of the product, nanocrystals of Pt and non‐noble metal alloys are diffic...
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Although aqueous synthesis of nanocrystals is advantageous in terms of the cost, convenience, environmental friendliness, and surface cleanness of the product, nanocrystals of Pt and non‐noble metal alloys are difficult to obtain with controlled morphology and composition from this synthesis owing to a huge gap between the reduction potentials of respective metal salts. This huge gap could now be remedied by introducing a sulfite into the aqueous synthesis, which is believed to resemble an electroless plating mechanism, giving rise to a colloid of Pt‐M (M=Ni, Co, Fe) alloy nanowires with an ultrasmall thickness (ca. 2.6 nm) in a high yield. The sulfite also leads to the formation of surface M−S bonds and thus atomic‐level Pt/M–S(OH) interfaces for greatly boosted hydrogen evolution kinetics under alkaline conditions. An activity of 75.3 mA cm −2 has been achieved with 3 μg of Pt in 1 m KOH at an overpotential of 70 mV, which is superior to previously reported catalysts.
Rational interface engineering via regulating the anchoring groups between molecular catalysts and light-absorbing semiconductors is essential and emergent to stabilize the semiconductor/molecular complex interaction ...
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Rational interface engineering via regulating the anchoring groups between molecular catalysts and light-absorbing semiconductors is essential and emergent to stabilize the semiconductor/molecular complex interaction and facilitate the photocarriers transport, thus realizing highly active and stable photoelectrochemical (PEC) water splitting. In this mini review, following a showcasing of the fundamental details of hybrid PEC systems containing semiconductor photoelectrodes and molecular catalysts for water splitting, the state-of-the-art progress of anchoring group regulation at semiconductor/molecular complex interface for efficient and stable PEC water splitting, as well as its effect on charge transfer kinetics, are comprehensively reviewed. Finally, potential research directions aimed at building high-efficiency hybrid PEC water splitting systems are summarized.
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