查看更多>>摘要：This work reports the synthesis,characterization,and energy focused applications of the novel lantha-nides co-doped tantalum pentoxide hetero-system(Sm3+-Eu3+-Tm3+∶Ta2O5).Ln3+-doped Ta2O5 express excellent opto-electronic features reflected by the narrow band gap energy of 3.87 eV.Different vibra-tions confirm the presence of Ta-O-Ta and Ta-O bonds.The synthesized system possesses ortho-rhombic geometry with 59.46 nm particle size.With the smoother and compact morphology,the synthesized material succeeds in augmenting the performance of different systems aimed at energy applications.Fully ambient perovskite solar cell device fabricated with the Ln3+-doped Ta2O5 as an electron transport layer excels in achieving an efficiency and fill factor of 14.17％and 76％under artificial sun.This device was marked by the negligible hysteresis behavior showing profound photovoltaic per-formance.The electrochemical activity of the Ln3+-doped Ta2O5 decorated electrode was evaluated for electrical charge storage potential with pseudocapacitive behavior.With the highest specific capacitance of 355.39 F/g and quicker ionic diffusion rate,the designed electrode excels conventionally used mate-rials.Electro-catalysis of water with Ln3+-doped Ta2O5 material indicates its capacity for H2 production with the lowest overpotential and Tafel slope values of 148 and 121.2 mV/dec,while the O2 generation is comparatively lower.With the stable electrochemical output,this rare earth modified material has the potential to replace conventionally used environmentally perilous and costly materials.
查看更多>>摘要：Thermal barrier coatings(TBCs)materials with lowered thermal and oxygen ion conductivity can provide thermal and oxidative protection for high temperature hot-end components in aeronautical engines and gas turbines.The rare-earth tantalate RETaO4(RE=Dy,Gd and Sm)ceramics with monoclinic(m)phase were successfully synthesized via spark plasma sintering.Oxygen vacancies responsible for the thermal and oxygen ion conductivities of RETaO4 were demonstrated by atomic-resolution energy dispersive X-ray and X-ray photoelectron spectroscopy.Among the three samples,DyTaO4 has excellent oxygen/thermal barrier performance.Compared to the current service thermal barrier coating material ZrO2-8 wt％Y2O3(8 YSZ),DyTaO4 has an ultra-low oxygen ion conductivity benefiting from low oxygen va-cancy concentration and strong stretching force constants.The intrinsic thermal conductivity of DyTaO4 is 68.2％less than that of 8 YSZ.Additionally,the thermal expansion rate curves indicate that the phase transformation does not happen from room temperature to 1200 ℃.The above results demonstrate that high-growth rate thermally grown oxide can be retarded by creating dense DyTaO4 coating with lowered thermal and oxygen ion conductivity.
查看更多>>摘要：The use of high-permittivity(high-k)thin films as gate dielectrics is essential in the development of low-power electronics.In this work,rare-earth thulium oxide(Tm2O3)thin films were prepared by a facile solution process and annealed at various temperatures from 400 to 700 ℃.The evolution of the physical and dielectric properties of Tm2O3 thin film with annealing temperature was investigated.It is demonstrated that the Tm2O3 thin film annealed at 600 ℃ exhibits the optimal performance,including a low leakage current of 3 × 10-10 A/cm2,a large areal capacitance of 250 nF/cm2 at 100 Hz,and a high permittivity value of 14.2.The Tm2O3 thin film as a gate insulator was integrated into the thin film transistor(TFT)employing In2O3-based semiconducting channels.The In2O3 TFT with 600 ℃-annealed Tm2O3 dielectric exhibits the superior performance,with a high Ion/Ioff of 1.65 × 107,a small subthreshold swing(SS)value of 0.2 V/dec,a VTH of+1.8 V,and a mobility of 1.68 cm2/(V·s).Furthermore,an inverter constructed by connecting the TFT with a resistor exhibits full-swing characteristics.This work provides a facile and appealing method for preparing the high-k Tm2O3 thin films as alternative gate dielectrics with the potential for use in low-power electronics and logic circuit applications.
查看更多>>摘要：At present,in-situ leaching of weathered crust elution-deposited rare earth ores(WCE-DREOs)encounter with problems such as long leaching cycles,slow infiltration rate and low product purity.In order to solve the above problems,the conventional leaching agent ammonium sulfate((NH4)2SO4)was com-pounded with polymeric surfactant polyethyleneimine(PEI)to form a composite leaching agent.The effects of leaching temperature,PEI concentration,flow rate and pH on leaching kinetics and perme-ability of rare earths(RE)and aluminum(Al)in orebody were studied.It is found that with temperature increasing,the time required to reach leaching equilibrium for both RE and Al is shortened,the apparent activation energies of RE and Al are 14.79 and 13.45 kJ/mol,respectively,and the leaching processes are in accordance with the outer diffusion control.When the concentrations of(NH4)2SO4 and PEI in the composite leaching agent are 2.0 wt％and 0.4 wt％,the time required to reach leaching equilibrium for RE and Al is about 50％shorter than that using(NH4)2SO4 alone,and the leaching efficiencies of RE are slightly higher than that of Al.Properly increasing the temperature and flow rate of the composite leaching agent can improve the leaching efficiencies of RE and Al,but pH has neglected effects on the leaching efficiencies of RE.At PEI concentrations below 0.4 wt％,the addition of PEI promotes the leaching of RE and Al.In column leaching studies of the WCE-DREO,the addition of 0.4 wt％PEI to the traditional leaching agent(NH4)2SO4 has no impact on the leaching efficiencies of RE.However,it can significantly increase the infiltration rate of WCE-DREO,shortening the leaching time per 10 mL effluent from about 30 min for(NH4)2SO4 leaching system to 20 min for the composite leaching system.The leaching time is shortened by one-third,and the leaching cost is reduced,which can provide theoretical guidance for the development and commercial implementation of novel composite leaching agent for WCE-DREO.
Zhihao GuoSultan Ahmed KhosoMengjie TianWei Sun...
1620-1628页
查看更多>>摘要：Bastnaesite((Ce,La,Pr,Nd)CO3F)is a significant light rare earth mineral found in nature,known for its fine-grained properties.Flotation is commonly employed for the recovery of fine-grained bastnaesite particles.Collectors serve as an essential flotation reagent that enhance the surface hydrophobicity of target minerals.A novel collector,N-hydroxy-9-octadecenamide(N-OH-9-ODA),was synthesised in this study.N-OH-9-ODA exhibits superior selectivity compared to the traditional collector oleic acid in the flotation separation of bastnaesite and fluorite.The experimental and computational results indicate that N-OH-9-ODA exhibits superior selectivity due to its higher adsorption affinity for bastnaesite surface compared to fluorite surface.The zeta potential and the binding energies of the Ce 3d peaks in the X-ray photoelectron spectrum(XPS)of bastnaesite surface exhibit significant shifts.Conversely,fluorite surface demonstrates minimal alterations in its zeta potential and the binding energies of the Ca 2p peaks in its XPS after its interaction with N-OH-9-ODA.
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