The oxygen evolution reaction（OER） is crucial for the electrocatalytic water electrolysis into oxygen and hydrogen,but the fourelectron transfer process hinders the OER *** realize the highly efficient water splitti...
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The oxygen evolution reaction（OER） is crucial for the electrocatalytic water electrolysis into oxygen and hydrogen,but the fourelectron transfer process hinders the OER *** realize the highly efficient water splitting,the nonprecious metal-based electrodes that can optimize the adsorption energy of intermediates and generate H2with low overpotential and robust stability are ***,we report a surface modification strategy to grow the trimetallic FeCoNi hydroxide on the amine linkersgrafted carbon cloth（CC-NH2@FeCoNi） by ***-NH2@FeCoNi possesses a superhydrophilic/superaerophobic surface,which could significantly enhance the mass transfer,and meanwhile promote the in situ generation of MOOH active ***,the superhydrophilic surface could facilitate the adsorption of abundant OH-ions,and repel the Cl-ions via electrostatic repulsive force during seawater ***,compared with the CC@FeCoNi that grown on the pure CC（320 mV）,the CC-NH2@FeCoNi needs an obviously smaller overpotential of 270 mV to achieve a current density of 100 mA cm-2,and meanwhile it exhibits a superior durability for 100 h at a current density of 200 m A cm-2in both alkaline water and *** strategy could be even applied universally in the preparation of other nonprecious metal hydroxides for efficient OER catalysis.
Biomass-derived hard carbon is becoming promising anodes for potassium-ion batteries（PIBs） thanks to their resource ***,it is a big challenge to improve the charge carrier kinetics of the disordered carbon lattice i...
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Biomass-derived hard carbon is becoming promising anodes for potassium-ion batteries（PIBs） thanks to their resource ***,it is a big challenge to improve the charge carrier kinetics of the disordered carbon lattice in hard ***,confined pitch-based soft carbon in pollen-derived hard carbon（PSC/PHC） is synthesized by vapor deposition strategy as anodes for *** ordered pitch-based soft carbon compensates for the short-range electron conduction in hard carbon to enhance the charge transfer kinetics,and the externally disordered pollen-derived hard carbon alleviates the volume change of soft carbon during *** from the synergistic effect of soft and hard carbon,as well as the reinforced structure of order-in-disordered carbon,the PSC/PHC obtained with deposition time of 0.5 h（PSC/PHC-0.5） displays an excellent rate capability(148.7 mAh g-1at 10 A g-1) and superb cycling stability(70% retention over 2000 cycles at 1 A g-1).This work offers a unique insight in tuning the microcrystalline structure of soft-hard carbon anode for advanced PIBs.
This study proposed a new cyclone separator, using a designed nozzle inside the traditional cyclone separator,which significantly improved the efficiency of separating fine particles while maintaining an essentially u...
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This study proposed a new cyclone separator, using a designed nozzle inside the traditional cyclone separator,which significantly improved the efficiency of separating fine particles while maintaining an essentially unchanged pressure drop. Firstly, computational fluid dynamics(CFD) was used to compare the flow characteristics of the new cyclone separator with those of the traditional cyclone separator. On this basis, this study comprehensively investigated the pressure drop and separation efficiency of two separators under varying working conditions. The new separator achieved a separation efficiency for particles with a particle size of 1 μm that was approximately 45% higher than that of the traditional separator when the inlet velocity was 2–10 m/s. Besides,the pressure drop of the cyclone separator remained unchanged while the separation efficiency increased by 46%at an inlet flow rate of 2 m/s. The influence of the outlet area of the nozzle inside the new cyclone separator on the separation efficiency and pressure drop was analyzed, and the outlet area of the nozzle with the best overall performance was determined. It was found that the overall performance of the new cyclone separator is optimal when the nozzle outlet area is S/f = 2 cm. Finally, an energy-saving cyclone separator with high separation efficiency was developed through an in-depth study of the variation of particle motion configuration with time. It is worth noting that this study provides a guidance for the flow field analysis and geometry optimization of new gassolid separators, not limited to cyclone separators.
A deep understanding of the electricity generation mechanism from the interaction between water molecules and carbon material surfaces is attractive for next-generation water-based energy conversion and storage ***,an...
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A deep understanding of the electricity generation mechanism from the interaction between water molecules and carbon material surfaces is attractive for next-generation water-based energy conversion and storage ***,an asymmetric generator was assembled based on functionalized carbon nanotubes films to investigate the relative contribution from various oxygen functional groups on carbon surface to the water-electrical *** and calculations demonstrate that the electricity mainly originates from the water molecule adsorption by carboxyl groups and dissociation of functional groups on carbon surface,which leads to the formation of electrical double layers at *** device allows the electricity generation with a variety of water sources,such as deionized water,tap water,as well as *** particular,the generator based on carboxyl carbon nanotubes can induce a voltage of over 200 mV spontaneously in natural seawater with the power density of about 0.11 mW·g^(−1).High voltages can be achieved easily through the series-connection strategy to power electronic products such as a liquid crystal *** work reveals the dominant role of carboxyl groups in carbon-based water–electricity conversion and is expected to offer inspiration for the preparation of carbon materials with high electrical performance.
Solar-driven desalination is a promising way to alleviate the freshwater shortage,while is facing challenges posed by low evaporation rates and severe salt ***,a high-performance twodimensional(2D) solar absorber with...
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Solar-driven desalination is a promising way to alleviate the freshwater shortage,while is facing challenges posed by low evaporation rates and severe salt ***,a high-performance twodimensional(2D) solar absorber with Co_(3)O_(4) nanoneedle arrays(Co_(3)O_(4)-NN) grown on the surface of reduced graphene oxide-coated pyrolyzed silk cloth(Co_(3)O_(4)-NN/rGO/PSC) was prepared,and a salt-free evaporator system was assembled based on the composite material and siphonage-the flowing water *** is revealed that the evaporation enthalpy of water can be reduced over the 2D solar absorber grown with Co_(3)O_(4)-NN_T enabling an evaporation rate of up to 2.35 kg m^(-2) h^(-1) in DI water under one solar *** desalination process can be carried out continuously even with salt concentration up to 20 wt%,due to the timely removal of concentrated brine from the interface with the assistance of directed flowing ***,the 2D structure and the flowing water also provide an opportunity to convert waste solar heat into electricity in the evaporator based on the seebeck effect,ensuring simultaneous freshwater production and power *** is believed that this work provides insights into designing hybrid systems with high evaporation rate,salt resistance,and electricity generation.
Gas-liquid-solid mini-fluidized beds known for high efficiency with controllable mass and heat transfer characteristics,have good application prospects in fields such as multiphase reaction process enhancement and int...
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Gas-liquid-solid mini-fluidized beds known for high efficiency with controllable mass and heat transfer characteristics,have good application prospects in fields such as multiphase reaction process enhancement and intrinsic kinetic *** three-phase mini-flow systems,the bed wall has a significant impact on spatiotemporal distribution of multi-phase flow structure,which influence the motion state of dispersed phase,make predicted phase holdup and residence time deviate from experimental ***,current research on the quantitative impact of bed walls on flow structures is still limited,which hinders the optimization design and industrial application of such *** this work,a meso-scale flow model of gas-liquid-solid mini-fluidized beds considering macro-scale effects between bed wall and flow is developed based on the principle of meso-scale science and introducing semi-theoretical formulas that take the effects of bed walls on particles and bubbles into *** calculated values of this model are in good agreement with experimental data,where prediction of phase holdup fits well with experimental results,the deviation of bubble size and terminal velocity are within 10%.Compared to existing models,this model demonstrates a higher level of accuracy in predicting the flow patterns of mini-fluidized beds,particularly those with pronounced wall *** research has laid a foundation for the design,scale-up and industrial application of mini-fluidized bed reactors.
Gas-liquid-solid circulating fluidized bed(GLSCFB)is an important type of chemical *** complex mesoscale flow structure of GLSCFB was described through the mesoscale flow structure parameters based on the energy-minim...
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Gas-liquid-solid circulating fluidized bed(GLSCFB)is an important type of chemical *** complex mesoscale flow structure of GLSCFB was described through the mesoscale flow structure parameters based on the energy-minimization multi-scale(EMMS)*** liquid-solid drag force model(Drag-ls model)was proposed and it was found that the drag coefficient between liquid and solid in three-phase systems increased compared to liquid-solid two-phase systems because of the influence of gas *** gas-solid drag force model(Drag-gs model)was proposed based on a modified unified wake ***,the combination of EMMS model and computational fluid dynamics(CFD)in GLSCFB was implemented,and the dynamic evolution process of particle clusters and distributions of gas holdup and solid holdup in GLSCFB were simulated more accurately by the *** simulation results indicate that the drag forces exerted on the solid phase by both the liquid and gas phases are coupled and mutually influence each *** simulated values of solid holdup may deviate from the experimental values if the interactions between the gas-solid and liquid-solid phases are corrected *** the average solid holdup of the bed is low,the mesoscale phenomena such as particle aggregation are not *** the solid holdup increases,there is a significant phenomenon of particle aggregation in the *** particles undergo a spatiotemporal evolution process of forming elongated clusters with high solid holdup,spherical clusters with high solid holdup,and clusters with low solid holdup which has large surface areas.
Batch-processing wet-etch reactors are the key equipment widely used in chip fabrication,and their performance is largely affected by the internal *** work develops a three-dimensional computational fluid dynamics(CFD...
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Batch-processing wet-etch reactors are the key equipment widely used in chip fabrication,and their performance is largely affected by the internal *** work develops a three-dimensional computational fluid dynamics(CFD)model considering heat generation of wet-etching reactions to investigate the fluid flow and heat transfer in the wet-etch *** backflow is observed below and above the wafer region,as the flow resistance in this region is *** temperature on the upper part of a wafer is higher due to the accumulation of reaction heat,and the average temperature of the side wafer is highest as its convective heat transfer is *** the gap between wafer and reactor wall can force the etchant to flow in the wafer region and then facilitate the convective heat transfer,leading to better within-wafer and wafer-to-wafer etch *** inlet angle of 60°balances fluid by-pass and mechanical energy loss,and it yields the best temperature and etch *** batch with 25wafers has much wider flow channels and much lower flow resistance compared with that with 50wafers,and thus it shows better temperature and etch *** results and the CFD model should serve to guide the optimal design of batch-processing wet-etch reactors.
Polyelectrolyte brushes(PEBs)are commonly used to modify surface that have attracted great research *** dielectric permittivity of the grafted surface is typically significantly different from that of solution,which r...
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Polyelectrolyte brushes(PEBs)are commonly used to modify surface that have attracted great research *** dielectric permittivity of the grafted surface is typically significantly different from that of solution,which results in surface polarization(SP)effect with a jump of electric *** is thus important to study how SP alters the PEB’s structure and *** this work,the SP effects on PEB structure was studied using a statistical thermodynamic *** free energy functional to describe SP effect was constructed by using the image-charge ***,the electrostatic potential was solved from a modified Poisson-Boltzmann equation taking the ion solvation effect into *** the absence of SP,the thickness of PEB exhibited a continuous collapse transition when decreasing the solvent *** the presence of SP,the collapse became a jump-like *** energy analysis showed that the long-range Coulombic interaction dominated the transition because of the enhanced counterion condensation in the presence of *** theory provides an effective tool to study SP effect on PEBs,and the results explain the underlying physics in PEB collapse transition.
The concentric internally heat-integrated distillation column(HIDi C) has advantages of low energy consumption and high thermodynamic efficiency. However, its drawbacks of limited heat transfer area,complex internal s...
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The concentric internally heat-integrated distillation column(HIDi C) has advantages of low energy consumption and high thermodynamic efficiency. However, its drawbacks of limited heat transfer area,complex internal structure, and large number of control parameters hinder its widespread industrial applications. To solve these challenges, in this work a novel sleeve-like concentric heat-integrated separation column, namely temperature-controlled phase change column(TCPC), was developed to separate liquid mixtures in a more effective and energy-saving way with reflux section being moved and trays being replaced with spiral corrugation blades. The comprehensive performances of TCPC in ethanol-water system was firstly evaluated by experiments. The results showed that TCPC performs well in ethanol-water separation due to the internal spiral corrugation significantly reducing the vapor-liquid contact in separation section. Meanwhile, compared to the concentric HIDi C, TCPC has a higher total heat transfer coefficient due to the larger heat transfer area. Computational fluid dynamics simulation reveals the internal design of TCPC inducing secondary vortices of the vapor, enhancing condensation heat transfer and separation efficiency. Further, increasing the mass flow rate within a certain range would enhance the comprehensive performance factor and lead to more effective separation.
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