Nitrogen-rich Eu2+-doped Ca-α-SiAlON phosphors(Cam/2-xSi12-m-nAlm+nOnN16-n:xEu) were synthesized by a freeze-drying assisted combustion synthesis(CS) route. Fast-synthesized products with high purity and uniform part...Nitrogen-rich Eu2+-doped Ca-α-SiAlON phosphors(Cam/2-xSi12-m-nAlm+nOnN16-n:xEu) were synthesized by a freeze-drying assisted combustion synthesis(CS) route. Fast-synthesized products with high purity and uniform particle morphology were confirmed by X-ray diffraction(XRD) and scanning electron microscopy(SEM). The analysis of lattice parameters by comparison with empirical equations showed that the as-prepared phosphors had low oxygen content. A series of samples were prepared according to the stoichiometry of Cam/2-0.08Si12-mAlmN16:0.08 Eu for further research. The influences of m value on the luminescence properties were investigated in detail. As m increased, a redshift phenomenon was observed in both the excitation and emission spectra. First-principle electronic structure calculations showed that the 3d energy level of Ca played an important role in the occurrence of the redshift phenomenon.展开更多
Developing bifunctional oxygen catalysts with high efficiency and low cost to replace platinum-group metal catalysts commonly utilized in metal-air batteries is critically desired.In this article,a convenient method t...Developing bifunctional oxygen catalysts with high efficiency and low cost to replace platinum-group metal catalysts commonly utilized in metal-air batteries is critically desired.In this article,a convenient method to synthesis NiFe nanoparticles hybridized with N-doped carbon nanotube(NiFe@N-CNTs)is reported.Electrocatalytic performance analysis indicates that Ni_(x)Fc_(1-x)@N-CNTs offers favorable oxygen reduction reaction(ORR)kinetics(onset potential(E_(onset))is 0.87 V and half-wave potential(E_(1/2))is0.84 V),together with excellent oxygen evolution reaction(OER)performance(an overpotential of 270 mV to drive10 mA·cm^(-2)).Contributed by the synergetic effect between NiFe alloy and N-CNTs,when being utilized as air cathode,rechargeable Zn-air batteries present superior cycling stability for over 150 h.This research provides a universal strategy to synthesize the hybrids of intertwined carbon nanotube matrix loaded with alloy nanoparticles.展开更多
基金This work was financially supported by the Chinese Academy of Sciences(CAS)Interdisciplinary Innovation Teamthe Fundamental Research Funds for the Central Universitiesthe Research Funds of Renmin University of China(No.19XNLG13).
文摘Nitrogen-rich Eu2+-doped Ca-α-SiAlON phosphors(Cam/2-xSi12-m-nAlm+nOnN16-n:xEu) were synthesized by a freeze-drying assisted combustion synthesis(CS) route. Fast-synthesized products with high purity and uniform particle morphology were confirmed by X-ray diffraction(XRD) and scanning electron microscopy(SEM). The analysis of lattice parameters by comparison with empirical equations showed that the as-prepared phosphors had low oxygen content. A series of samples were prepared according to the stoichiometry of Cam/2-0.08Si12-mAlmN16:0.08 Eu for further research. The influences of m value on the luminescence properties were investigated in detail. As m increased, a redshift phenomenon was observed in both the excitation and emission spectra. First-principle electronic structure calculations showed that the 3d energy level of Ca played an important role in the occurrence of the redshift phenomenon.
基金financially supported by the National Natural Science Foundation of China (No.52072033)
文摘Developing bifunctional oxygen catalysts with high efficiency and low cost to replace platinum-group metal catalysts commonly utilized in metal-air batteries is critically desired.In this article,a convenient method to synthesis NiFe nanoparticles hybridized with N-doped carbon nanotube(NiFe@N-CNTs)is reported.Electrocatalytic performance analysis indicates that Ni_(x)Fc_(1-x)@N-CNTs offers favorable oxygen reduction reaction(ORR)kinetics(onset potential(E_(onset))is 0.87 V and half-wave potential(E_(1/2))is0.84 V),together with excellent oxygen evolution reaction(OER)performance(an overpotential of 270 mV to drive10 mA·cm^(-2)).Contributed by the synergetic effect between NiFe alloy and N-CNTs,when being utilized as air cathode,rechargeable Zn-air batteries present superior cycling stability for over 150 h.This research provides a universal strategy to synthesize the hybrids of intertwined carbon nanotube matrix loaded with alloy nanoparticles.