AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(...AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),photoluminescence(PL)spectroscopy,electron spin resonance(ESR)spectroscopy,transient photocurrent and electrochemical impedance spectroscopy(EIS)were used to characterize binary composites.Tetracycline(TC)was used as a substrate to study the performance efficiency of the degradation of photocatalysts under light conditions,and the degradation effect of TC was also evaluated under different mass concentrations and ionic contents.In addition,we further investigated the photocatalytic mechanism of the binary composite material AgVO_(3)/ZIF-8 and identified the key active components responsible for the catalytic degradation of this new photocatalyst.The experimental results show that the degradation efficiency of 10%-AZ,prepared with a molar ratio of 10%AgVO_(3)and ZIF-8 to TC,was 75.0%.This indicates that the photocatalytic activity can be maintained even under a certain ionic content,making it a suitable photocatalyst for optimal use.In addition,the photocatalytic mechanism of binary composites was further studied by the active species trapping experiment.展开更多
Lu_(2)SiO_(5):Ce(LSO:Ce)serving as a core material for radiation detectors,plays a crucial role in the design and development of positron emission tomography(PET)devices.Experiment has confirmed that low concentration...Lu_(2)SiO_(5):Ce(LSO:Ce)serving as a core material for radiation detectors,plays a crucial role in the design and development of positron emission tomography(PET)devices.Experiment has confirmed that low concentration of Al doping can significantly enhance the light yield,decay time,rise time,energy resolution,and afterglow level of the LSO:Ce crystals.The mechanisms regarding the lattice site occupancy of Al in LSO,while closely associated with the performance improvements,are not yet fully understood.Particularly,it is unclear either the ionic radius or the chemical valence plays a more critical role in determining the site occupancy.In this study,we utilized first-principles calculations based on density functional theory(DFT)to study the lattice site occupancy of Al in LSO crystals and to explore their impact on the electronic structure.Our results indicate that with changes in the growth environment,as reflected by the atomic chemical potentials,Al can occupy either the Si sites or the Lu_(2)sites,and it is not inclined to occupy the Lu_(1) sites.The doping of Al at the Si site introduces a shallow acceptor level,which may contribute to the suppression of trap concentration and affect the ratio of Ce^(3+)to Ce^(4+)within the crystal,thereby influencing its scintillation properties.展开更多
文摘AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),photoluminescence(PL)spectroscopy,electron spin resonance(ESR)spectroscopy,transient photocurrent and electrochemical impedance spectroscopy(EIS)were used to characterize binary composites.Tetracycline(TC)was used as a substrate to study the performance efficiency of the degradation of photocatalysts under light conditions,and the degradation effect of TC was also evaluated under different mass concentrations and ionic contents.In addition,we further investigated the photocatalytic mechanism of the binary composite material AgVO_(3)/ZIF-8 and identified the key active components responsible for the catalytic degradation of this new photocatalyst.The experimental results show that the degradation efficiency of 10%-AZ,prepared with a molar ratio of 10%AgVO_(3)and ZIF-8 to TC,was 75.0%.This indicates that the photocatalytic activity can be maintained even under a certain ionic content,making it a suitable photocatalyst for optimal use.In addition,the photocatalytic mechanism of binary composites was further studied by the active species trapping experiment.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFB3503900)the National Natural Science Foundation of China(Grant No.12305212)。
文摘Lu_(2)SiO_(5):Ce(LSO:Ce)serving as a core material for radiation detectors,plays a crucial role in the design and development of positron emission tomography(PET)devices.Experiment has confirmed that low concentration of Al doping can significantly enhance the light yield,decay time,rise time,energy resolution,and afterglow level of the LSO:Ce crystals.The mechanisms regarding the lattice site occupancy of Al in LSO,while closely associated with the performance improvements,are not yet fully understood.Particularly,it is unclear either the ionic radius or the chemical valence plays a more critical role in determining the site occupancy.In this study,we utilized first-principles calculations based on density functional theory(DFT)to study the lattice site occupancy of Al in LSO crystals and to explore their impact on the electronic structure.Our results indicate that with changes in the growth environment,as reflected by the atomic chemical potentials,Al can occupy either the Si sites or the Lu_(2)sites,and it is not inclined to occupy the Lu_(1) sites.The doping of Al at the Si site introduces a shallow acceptor level,which may contribute to the suppression of trap concentration and affect the ratio of Ce^(3+)to Ce^(4+)within the crystal,thereby influencing its scintillation properties.
