Ce3+/Dy3+/Tb3+/Eu3+/Mn2+and Cr3+ions co-doped Zn3 Al2 Ge2 O10 phosphor were prepared by a hightemperature solid-state method.X-ray diffraction patterns prove the cubic phase structure of prepared Zn3 Al2 Ge2 O10 phosp...Ce3+/Dy3+/Tb3+/Eu3+/Mn2+and Cr3+ions co-doped Zn3 Al2 Ge2 O10 phosphor were prepared by a hightemperature solid-state method.X-ray diffraction patterns prove the cubic phase structure of prepared Zn3 Al2 Ge2 O10 phosphor,Emission,excitation spectra and decay curves confirm the tunable luminescence.Different degrees of the decrease of emission FWHM in Zn3 Al2 Ge2 O10:0.02 Cr3+,RE(RE=Ce3+,Dy3+,Tb3+,Eu3+)and Zn3 Al2 Ge2 O10:0.02 Cr3+,Mn2+are observed.The reason of variable FWHM is the effect of crystal field splitting and nephelauxetic effect,and the nephelauxetic effect is dominant.Therefore,the emission FWHM decreases with the increasing concentration of Mn2+/Tb3+/Eu3+in Zn3 Al2 Ge2 O10:0.02 Cr3+,and for Zn3 Al2 Ge2 O10:0.02 Cr3+,Ce3+and Zn3 Al2 Ge2 O10:0.02 Cr3+,Dy3+,it is a constant.The variation of Zn3 Al2 Ge2 O10:0.02 Cr3+,Tb3+is more obvious than that of Zn3 Al2 Ge2 O10:0.02 Cr3+,Eu3+,because Tb3+ion has smaller electronegativity.Thus,the tunable luminescence of Cr3+can be realized by co-doping different ions.And these phosphors have potential applications in light-emitting diodes for plant growth.展开更多
TiO2 powder and TiO2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method.The influences of different doping Cr3+ concentration on the photocatalytic activity of TiO2 were discussed, UV-visi...TiO2 powder and TiO2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method.The influences of different doping Cr3+ concentration on the photocatalytic activity of TiO2 were discussed, UV-visible and X-ray diffraction analysis were used to test the performance of TiO2 powder and film. The results indicate that photocatalytic activity of doping Cr3+-TiO2 thin film is higher than that of powder, and the interaction between Cr3+-doped and substrate can greatly enhance the photocatalytic activity. The results of X-ray diffraction and photoabsorption show that the Cr3+ -doped energy level in TiO2 is 0. 62 eV high from the top of valence band, which belongs to the type of deep energy level doping. On the basis of the semiconductor energy level theory and Cr3+ dopant energy level, the semiconductor energy level model of Cr3+ in TiO2 powder and thin film were established, and the doping mechanisms of Cr3+-doped in TiO2 powder and thin film were analyzed.展开更多
基金Projects supported by the National Natural Science Foundation of China(61575019,11474018,61775013),ChinaThe authors express the thanks to the Fundamental ResearchFunds for the Central Universities under Grant No. 2018YJS166,China and the Fundamental Research Funds for the Central Universitieswith the Grant No. 2016JBM066,No. 2017RC015, No.2017JBZ105, China.
文摘Ce3+/Dy3+/Tb3+/Eu3+/Mn2+and Cr3+ions co-doped Zn3 Al2 Ge2 O10 phosphor were prepared by a hightemperature solid-state method.X-ray diffraction patterns prove the cubic phase structure of prepared Zn3 Al2 Ge2 O10 phosphor,Emission,excitation spectra and decay curves confirm the tunable luminescence.Different degrees of the decrease of emission FWHM in Zn3 Al2 Ge2 O10:0.02 Cr3+,RE(RE=Ce3+,Dy3+,Tb3+,Eu3+)and Zn3 Al2 Ge2 O10:0.02 Cr3+,Mn2+are observed.The reason of variable FWHM is the effect of crystal field splitting and nephelauxetic effect,and the nephelauxetic effect is dominant.Therefore,the emission FWHM decreases with the increasing concentration of Mn2+/Tb3+/Eu3+in Zn3 Al2 Ge2 O10:0.02 Cr3+,and for Zn3 Al2 Ge2 O10:0.02 Cr3+,Ce3+and Zn3 Al2 Ge2 O10:0.02 Cr3+,Dy3+,it is a constant.The variation of Zn3 Al2 Ge2 O10:0.02 Cr3+,Tb3+is more obvious than that of Zn3 Al2 Ge2 O10:0.02 Cr3+,Eu3+,because Tb3+ion has smaller electronegativity.Thus,the tunable luminescence of Cr3+can be realized by co-doping different ions.And these phosphors have potential applications in light-emitting diodes for plant growth.
基金Project (20466001) supported by the National Natural Science Foundation of China
文摘TiO2 powder and TiO2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method.The influences of different doping Cr3+ concentration on the photocatalytic activity of TiO2 were discussed, UV-visible and X-ray diffraction analysis were used to test the performance of TiO2 powder and film. The results indicate that photocatalytic activity of doping Cr3+-TiO2 thin film is higher than that of powder, and the interaction between Cr3+-doped and substrate can greatly enhance the photocatalytic activity. The results of X-ray diffraction and photoabsorption show that the Cr3+ -doped energy level in TiO2 is 0. 62 eV high from the top of valence band, which belongs to the type of deep energy level doping. On the basis of the semiconductor energy level theory and Cr3+ dopant energy level, the semiconductor energy level model of Cr3+ in TiO2 powder and thin film were established, and the doping mechanisms of Cr3+-doped in TiO2 powder and thin film were analyzed.
基金National Natural Science Foundation of China (21107111)Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-EW-403) for the support~~
