Facile and effective synthesis strategy for terbium-doped hydroxyapatite toward photoelectric devices and flexible functional fibers

As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP.

Metal halide perovskite nanocrystals with enhanced photoluminescence and stability toward anti-counterfeiting highperformance flexible fibers

As a new type of light-collecting and luminescent material,all-inorganic cesium lead halide CsPbX_(3)(X=Cl,Br,I)perovskite nanocrystals(NCs)are expected to have a wide range of applications in the fields of photovoltaics,optoelectronics,and fluorescence anti-counterfeiting,etc.Therefore,improving the fluorescence performance and stability of CsPbX_(3)perovskite NCs to prompt their applications would promise both fundamental and practical significance for in-depth research in the field of halide perovskites.In this paper,we developed a modification strategy to introduce a halogen source,zinc bromide(ZnBr_(2))in hexane,to CsPbX_(3)perovskite that can be conducted under atmospheric conditions with reduced reaction cost and easier operation.The first work in this paper was to apply the modification strategy to CsPbI_(3)nanowires(NWs).Compared with the untreated NWs,the ZnBr_(2)/hexane modified CsPbI_(3)NWs exhibited better fluorescence properties.Subsequently,based on the study of perovskite NWs,we investigated perovskite nanocrystal-CsPbI_(3)nanorods(NRs)with different morphologies and sizes.It was found that the luminescence properties of nanorods(NRs)were superior.Later,we infiltrated the modified NRs into the aramid/polyphenylene sulfide(ACFs/PPS)composite paper yielded from our previous work to study its fluorescence performance for anti-counterfeiting.Their luminescence properties under ultraviolet light irradiation enable better performance in fluorescence anti-counterfeiting.The ZnBr_(2)/hexane modification strategy and the applications studied in this work will expand the scope of perovskite research,laying the foundation for the applications of fluorescent anti-counterfeiting,nano-photoelectric devices,and fluorescent composite materials.

Structure and luminescence properties of color-tunable phosphor Sr_(2)La_(3)(SiO_(4))_(3)F:Tb^(3+),Sm^(3+)

A series of single-phase and color-tunable phosphors Sr_(2)La_(3)(SiO_(4))_(3)F:0.15Tb^(3+),xSm^(3+)(SLSOF:0.15Tb^(3+),xSm^(3+)) was prepared using solid-state route.The X-ray diffraction(XRD) was used to characterize the phase of the as-prepared samples.The synthesized phosphors have apatite-type structure without other impurities.Sm^(3+) and Tb^(3+) ions substitute La^(3+) into the lattice and form a single-phase solid solution.The elements are evenly distributed in the sample according to the scanning electron microscopy(SEM) results.The crystal structure of the host phosphor was refined by the Rietveld method.The optical properties were studied in detail by investigation of the luminescence and diffuse spectra,fluorescence decay curves and energy transfer efficiency.The phosphor color can be changed from green(0.29,0.48) to yellow/orange and red(0.57,0.42) via adjusting the doping ratio of Sm^(3+).The SLSOF:0.15Tb^(3+),xSm^(3+)phosphors can emit typical multicolor light such as green,yellow,orange and red with gradually increasing Sm^(3+)doping concentration.All results indicate the occurrence of the energy transfer which results in the color-tunable properties of the phosphors.

Floret-like Fe-N_(x)nanoparticle-embedded porous carbon superstructures from a Fe-covalent triazine polymer boosting oxygen electroreduction

Fe–N_(x)nanoparticles-embedded porous carbons with a desirable superstructure have attracted immense attention as promising catalysts for electrochemical oxygen reduction reaction.Herein,we employed Fe-coordinated covalent triazine polymer for the fabrication of Fe–N_(x)nanoparticle-embedded porous carbon nanoflorets(Fe/N@CNFs)employing a hypersaline-confinement-conversion strategy.Presence of tailored N types within the covalent triazine polymer interwork in high proportions contributes to the generation of Fe/N coordination and subsequent Fe–N_(x)nanoparticles.Owing to the utilization of NaCl crystals,the resultant Fe/N@CNF-800 which was generated by pyrolysis at 800℃showed nanoflower structure and large specific surface area,which remarkably suppressed the agglomeration of high catalytic active sites.As expect,the Fe/N@CNF-800 exhibited unexpected oxygen reduction reaction catalytic performance with an ultrahigh half-wave potential(0.89 V vs.reversible hydrogen electrode),a dominant 4e–transfer approach and great cycle stability(>92%after 100000 s).As a demonstration,the Fe/N-PCNF-800-assembled zinc–air battery delivered a high open circuit voltage of 1.51 V,a maximum peak power density of 164 mW·cm^(-2),as well as eminent rate performance,surpassing those of commercial Pt/C.This contribution offers a valuable avenue to exploit efficient metal nanoparticles-based carbon catalysts towards energy-related electrocatalytic reactions and beyond.