High-surface-area ZnO nanosheets are prepared using a template-assisted hydrothermal method.A saturation moment as high as 0.02 emu/g is obtained for the ZnO nanosheets.Both photoluminescence spectroscopy and x-ray ph...High-surface-area ZnO nanosheets are prepared using a template-assisted hydrothermal method.A saturation moment as high as 0.02 emu/g is obtained for the ZnO nanosheets.Both photoluminescence spectroscopy and x-ray photoelectron spectroscopy demonstrate the existence of abundant oxygen vacancies on the surfaces of the nanosheets.In addition,the oxygen vacancy concentration increases with an increasing nanosheet surface area.The results show that the origin of the room-temperature ferromagnetism is closely related with a large surface area and oxygen vacancies of the nanosheets.This finding suggests that the high-surface-area ZnO nanosheets are promising to be applied to spintronic devices.展开更多
Metal halide perovskites have attracted much attention in biomedicine because of their excellent fluorescence energy conversion properties;however,poor water-stability and cytotoxicity limit its applications as a biom...Metal halide perovskites have attracted much attention in biomedicine because of their excellent fluorescence energy conversion properties;however,poor water-stability and cytotoxicity limit its applications as a biomedical tracer,especially in cellular imaging.Herein,water-ultrastable perovskites C sPbBr_(3):Cs_(4)PbBr_(6)nanocrystals(NCs)encapsulated in chitosan are fabricated successfully using a water-triggered method.The as-synthesized CsPbBr_(3):Cs_(4)PbBr_(6)@CS(chitosan,CS)nanoparticles in water display enhanced fluorescence emission for 35 days.Further,the viability of glioma cells(U87 cells)incubated with different concentrations of CsPbBr_(3):Cs_(4)PbBr_(6)@CS nanoparticles(0-20μg·ml^(-1))for24 h is found to be higher than 90%.In artificial body fluid,analyses using laser confocal microscopy,the standard Cell Counting Kit-8(CCK-8)method,and flow cytometry demonstrated the good water ultrastability and high biocompatibility performance of CsPbBr_(3):Cs_(4)PbBr_(6)@CS nanoparticles in cellular imaging.Overall,the water-ultrastable halide perovskites support promising perspectives in biological cell tracing and intelligent medical technology.展开更多
A series of lanthanide complexes [Ln(4-Cl-2-MOBA)3phen]2(Ln=Sm(1), Nd(2), Ho(3), Eu(4), Dy(5), and Tb(6); 4-Cl-2-MOBA=4-chloro-2-methoxybenzoate, phen=1,10-phenanthroline) were synthesized and characterized. The singl...A series of lanthanide complexes [Ln(4-Cl-2-MOBA)3phen]2(Ln=Sm(1), Nd(2), Ho(3), Eu(4), Dy(5), and Tb(6); 4-Cl-2-MOBA=4-chloro-2-methoxybenzoate, phen=1,10-phenanthroline) were synthesized and characterized. The single-crystal X-ray diffraction demonstrates that 1–3 are isomorphous, which present dimeric structures with four 4-Cl-2-MOBA anions function as bridging ligands. Complexes 1 and 4–6 display their characteristic luminescence emission bands of central Ln3?ions. The heat capacities, the thermodynamic functions and the thermogravimetry–Fourier transform infrared spectra of gaseous products of complexes 1–6 were investigated.Their non-isothermal kinetics of the second decomposition stage was studied by the integral isoconversional non-linear method and Stark method. Furthermore, 1–6 exhibited excellent antibacterial activity against Candida albicans,Escherichia coli and Staphylococcus aureu.展开更多
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0201001the National Natural Science Foundation of China under Grant No 11574071+1 种基金the Natural Science Foundation for Outstanding Young Researcher in Hebei Province under Grant No E2016210093the Natural Science Foundation of Hebei Province under Grant No A2018210123
文摘High-surface-area ZnO nanosheets are prepared using a template-assisted hydrothermal method.A saturation moment as high as 0.02 emu/g is obtained for the ZnO nanosheets.Both photoluminescence spectroscopy and x-ray photoelectron spectroscopy demonstrate the existence of abundant oxygen vacancies on the surfaces of the nanosheets.In addition,the oxygen vacancy concentration increases with an increasing nanosheet surface area.The results show that the origin of the room-temperature ferromagnetism is closely related with a large surface area and oxygen vacancies of the nanosheets.This finding suggests that the high-surface-area ZnO nanosheets are promising to be applied to spintronic devices.
基金financially supported by the National Natural Science Foundation of China(Nos.U2130128,11772207)the Natural Science Foundation of Hebei Province(Nos.A2019210204,H2022205047)+4 种基金the Central Government Guiding Local Science and Technology Development Project(No.216Z4302G)the Natural Science Foundation of Hebei Education Department(No.ZD2020192)the Youth Top-notch Talents Supporting Plan of Hebei ProvinceNational Key Research and Development Program of China(No.2016YFC0904503)Hebei Administration for Market Supervision Science and Technology Project List(2023ZC03)。
文摘Metal halide perovskites have attracted much attention in biomedicine because of their excellent fluorescence energy conversion properties;however,poor water-stability and cytotoxicity limit its applications as a biomedical tracer,especially in cellular imaging.Herein,water-ultrastable perovskites C sPbBr_(3):Cs_(4)PbBr_(6)nanocrystals(NCs)encapsulated in chitosan are fabricated successfully using a water-triggered method.The as-synthesized CsPbBr_(3):Cs_(4)PbBr_(6)@CS(chitosan,CS)nanoparticles in water display enhanced fluorescence emission for 35 days.Further,the viability of glioma cells(U87 cells)incubated with different concentrations of CsPbBr_(3):Cs_(4)PbBr_(6)@CS nanoparticles(0-20μg·ml^(-1))for24 h is found to be higher than 90%.In artificial body fluid,analyses using laser confocal microscopy,the standard Cell Counting Kit-8(CCK-8)method,and flow cytometry demonstrated the good water ultrastability and high biocompatibility performance of CsPbBr_(3):Cs_(4)PbBr_(6)@CS nanoparticles in cellular imaging.Overall,the water-ultrastable halide perovskites support promising perspectives in biological cell tracing and intelligent medical technology.
基金supported by the National Natural Science Foundation of China (21073053, 21173067 and 20773034)the Natural Science Foundation of Hebei Province (B2012205022, B2011205037)
文摘A series of lanthanide complexes [Ln(4-Cl-2-MOBA)3phen]2(Ln=Sm(1), Nd(2), Ho(3), Eu(4), Dy(5), and Tb(6); 4-Cl-2-MOBA=4-chloro-2-methoxybenzoate, phen=1,10-phenanthroline) were synthesized and characterized. The single-crystal X-ray diffraction demonstrates that 1–3 are isomorphous, which present dimeric structures with four 4-Cl-2-MOBA anions function as bridging ligands. Complexes 1 and 4–6 display their characteristic luminescence emission bands of central Ln3?ions. The heat capacities, the thermodynamic functions and the thermogravimetry–Fourier transform infrared spectra of gaseous products of complexes 1–6 were investigated.Their non-isothermal kinetics of the second decomposition stage was studied by the integral isoconversional non-linear method and Stark method. Furthermore, 1–6 exhibited excellent antibacterial activity against Candida albicans,Escherichia coli and Staphylococcus aureu.
