By synthesizing reactive powders via a self-sustaining combustion synthesis, the glycine-nitrate process, the gadolinium-doped celia （GDC） with the chemical formula Ce0.8Gd0.2O1.9 was prepared. The resultant powders...By synthesizing reactive powders via a self-sustaining combustion synthesis, the glycine-nitrate process, the gadolinium-doped celia （GDC） with the chemical formula Ce0.8Gd0.2O1.9 was prepared. The resultant powders were dispersed with the terpineol as the dispersant through different methods such as ball milling and high-shear dispersing. Coagulation factor （CF） was used to mark the degree of agglomeration on the nano-scale GDC in this work. The effect of agglomeration on the densification behavior at different sintering temperatures was investigated. The studies indicated that agglomeration retarded the densification at the sintering stage. The powders with better dispersion exhibited a higher sintered density at the same temperature. After effective dispersion treatment, GDC could be fully densified at the sintering temperature of 1300 ℃. The densification temperature was significantly lower than those reported previously. The high sintering kinetics of the ceramics was obtained based on the agglomeration control.展开更多
Cerium oxide(CeO_(2)),or ceria,and its doped derivatives have been extensively studied for several decades and are well-known oxides valued for their unique structural properties and wide range of applications.These m...Cerium oxide(CeO_(2)),or ceria,and its doped derivatives have been extensively studied for several decades and are well-known oxides valued for their unique structural properties and wide range of applications.These materials play a crucial role in sustainable development within society.Structural modification through de fect e ngineering of the highly stable cubic fluorite phase enhances the versatility of this doped ceria to a new level.Among the numerous dopants of the CeO_(2)matrix,ceria doped with gadolinium(Gd),known as Ce_(1-x)Gd_(x)O_(2-■)(CGO),is gaining popularity due to its multifunctionality.The introduction of defect-induced vacancies in the oxygen sublattice(V_(o))and a change in the average valence of cerium(Ce^(3+)/Ce^(4+))are primarily responsible for the improved performance compared to pristine CeO_(2).These materials are currently undergoing intensive research for potential use as electrolytes in intermediate-temperature solid oxide fuel cells(IT-SOFCs)and dense oxygen-permeable membranes(OPMs).Additionally,they are being commercially utilized for power generation and oxygen separation.CGO materials are also attracting significant attention in various fields such as optics,photocatalysis,electrostriction,spintronics,gas sensing,electrocatalysis,and biomedical applications.This review paper aims to compile the latest contributions to CGO materials and comprehensively cover their various application areas.The crystal structure,defect equilibrium in Gd^(3+)-doped CeO_(2),the origin of multifunctionality,and the prospects of these materials are also exclusively discussed.展开更多
Gadolinium-doped ceria(GDC)interlayers are required to prevent the interfacial reaction between La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3)(LSCF)cathode and Y_(2)O_(3)-stabilized ZrO 2(YSZ)electrolyte in solid oxide fuel ce...Gadolinium-doped ceria(GDC)interlayers are required to prevent the interfacial reaction between La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3)(LSCF)cathode and Y_(2)O_(3)-stabilized ZrO 2(YSZ)electrolyte in solid oxide fuel cells(SOFCs).However,it's difficult to prepare a thin and dense GDC interlayer on the sintered half-cell at a low temperature.In this study,the physical vapor deposition(PVD)method was employed to success-fully manufacture dense GDC interlayers with the thickness of 1 m m.The influences of GDC sintering temperature(900℃,1000℃ and 1100℃)on cell performance characteristics and degradation behavior were investigated.The cell with GDC interlayer sintered at 1100?C showed the lowest degradation rate during the 216-h operation.The best stability was attributed to the most effective inhibition of Sr diffusion by the GDC interlayer,which was demonstrated by the almost unchanged Ohmic and polari-zation resistances during the aging stage and the negligible Sr enrichment at YSZ/GDC interface.Compared to the conventional screen-printed GDC interlayers(sintered above 1250℃),the GDC inter-layer prepared by the PVD method and sintered at 1100℃ was significantly denser and thinner,showing a promising application prospect due to its benefits for cell stability.展开更多
A cheap method allowing fabrication of biocompatible,ultra-small(2-10 nm)and fluorescent(λ_(em)=425-500 nm)nanohybrids(NHs)from coffee wastes is reported.The gadolinium-doped nanohybrids(GDNHs)or gadolinium-free carb...A cheap method allowing fabrication of biocompatible,ultra-small(2-10 nm)and fluorescent(λ_(em)=425-500 nm)nanohybrids(NHs)from coffee wastes is reported.The gadolinium-doped nanohybrids(GDNHs)or gadolinium-free carbon dots(GFCDs)can be synthesized in a domestic microwave oven according to green synthesis principles.Hydrodynamic sizes,chemical composition,impact on proton magnetic resonance relaxation time and optical properties of the GDNHs and GFCDs were studied in details and compared.In particular,doping of the NHs with Gd^(3+)ions,up to 1.87%w/w of gadolinium per particles’weight,will allow their application for magnetic resonance imaging(MRI).Furthermore,cell culture tests on human adenocarcinomic alveolar basal epithelial cells line(A549)have shown high biocompatibility of the GDNHs and in a wide concentration range 100-1000μg/ml.展开更多
基金Project supported by the Key Research Programof the National Natural Science Foundation (90610035)
文摘By synthesizing reactive powders via a self-sustaining combustion synthesis, the glycine-nitrate process, the gadolinium-doped celia （GDC） with the chemical formula Ce0.8Gd0.2O1.9 was prepared. The resultant powders were dispersed with the terpineol as the dispersant through different methods such as ball milling and high-shear dispersing. Coagulation factor （CF） was used to mark the degree of agglomeration on the nano-scale GDC in this work. The effect of agglomeration on the densification behavior at different sintering temperatures was investigated. The studies indicated that agglomeration retarded the densification at the sintering stage. The powders with better dispersion exhibited a higher sintered density at the same temperature. After effective dispersion treatment, GDC could be fully densified at the sintering temperature of 1300 ℃. The densification temperature was significantly lower than those reported previously. The high sintering kinetics of the ceramics was obtained based on the agglomeration control.
基金Project supported by the Indian Council of Medical Research(#5/3/8/30/ITR-f/2018-ITR)National Research Foundation of Korea(RS-2023-00278268)。
文摘Cerium oxide(CeO_(2)),or ceria,and its doped derivatives have been extensively studied for several decades and are well-known oxides valued for their unique structural properties and wide range of applications.These materials play a crucial role in sustainable development within society.Structural modification through de fect e ngineering of the highly stable cubic fluorite phase enhances the versatility of this doped ceria to a new level.Among the numerous dopants of the CeO_(2)matrix,ceria doped with gadolinium(Gd),known as Ce_(1-x)Gd_(x)O_(2-■)(CGO),is gaining popularity due to its multifunctionality.The introduction of defect-induced vacancies in the oxygen sublattice(V_(o))and a change in the average valence of cerium(Ce^(3+)/Ce^(4+))are primarily responsible for the improved performance compared to pristine CeO_(2).These materials are currently undergoing intensive research for potential use as electrolytes in intermediate-temperature solid oxide fuel cells(IT-SOFCs)and dense oxygen-permeable membranes(OPMs).Additionally,they are being commercially utilized for power generation and oxygen separation.CGO materials are also attracting significant attention in various fields such as optics,photocatalysis,electrostriction,spintronics,gas sensing,electrocatalysis,and biomedical applications.This review paper aims to compile the latest contributions to CGO materials and comprehensively cover their various application areas.The crystal structure,defect equilibrium in Gd^(3+)-doped CeO_(2),the origin of multifunctionality,and the prospects of these materials are also exclusively discussed.
基金This work was supported by the National Key R&D Program of China(2018YFB1502202)Tsinghua University Initiative Scien-tific Research Program(20193080038).
文摘Gadolinium-doped ceria(GDC)interlayers are required to prevent the interfacial reaction between La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3)(LSCF)cathode and Y_(2)O_(3)-stabilized ZrO 2(YSZ)electrolyte in solid oxide fuel cells(SOFCs).However,it's difficult to prepare a thin and dense GDC interlayer on the sintered half-cell at a low temperature.In this study,the physical vapor deposition(PVD)method was employed to success-fully manufacture dense GDC interlayers with the thickness of 1 m m.The influences of GDC sintering temperature(900℃,1000℃ and 1100℃)on cell performance characteristics and degradation behavior were investigated.The cell with GDC interlayer sintered at 1100?C showed the lowest degradation rate during the 216-h operation.The best stability was attributed to the most effective inhibition of Sr diffusion by the GDC interlayer,which was demonstrated by the almost unchanged Ohmic and polari-zation resistances during the aging stage and the negligible Sr enrichment at YSZ/GDC interface.Compared to the conventional screen-printed GDC interlayers(sintered above 1250℃),the GDC inter-layer prepared by the PVD method and sintered at 1100℃ was significantly denser and thinner,showing a promising application prospect due to its benefits for cell stability.
基金the support of EU Horizon 2020 Research and Innovation Staff Exchange Programme(RISE)under Marie Skłodowska-Curie Action(project 101008159“UNAT”).
文摘A cheap method allowing fabrication of biocompatible,ultra-small(2-10 nm)and fluorescent(λ_(em)=425-500 nm)nanohybrids(NHs)from coffee wastes is reported.The gadolinium-doped nanohybrids(GDNHs)or gadolinium-free carbon dots(GFCDs)can be synthesized in a domestic microwave oven according to green synthesis principles.Hydrodynamic sizes,chemical composition,impact on proton magnetic resonance relaxation time and optical properties of the GDNHs and GFCDs were studied in details and compared.In particular,doping of the NHs with Gd^(3+)ions,up to 1.87%w/w of gadolinium per particles’weight,will allow their application for magnetic resonance imaging(MRI).Furthermore,cell culture tests on human adenocarcinomic alveolar basal epithelial cells line(A549)have shown high biocompatibility of the GDNHs and in a wide concentration range 100-1000μg/ml.
