Template Preparation And Luminescence Properties Of BCNO

In this paper,BCNO luminescent material was prepared by template method using boric acid（H₃BO₃,B source）and urea（CO（NH₂）₂,N source）as raw materials,melamine sponge and bamboo fiber as templates.The influences of reaction conditions on the structure morphology and luminescent properties of BCNO luminescent material was discussed by changing the sintering temperature,molar ratio of raw materials and sintering time.Subsequently,BCNO（24）/PVA composites film could be applied to the detection of inorganic transition metal ion chromium.There were three main parts in this paper:Firstly,using bamboo fiber as template,a series of BCNO luminescent material was obtained at different sintering temperatures and sintering times under different feed ratios of boric acid and urea.The obtained product was characterized by FTIR and XRD analysis,indicating that BCNO luminescent material was successfully synthesized.The SEM results show that with the increase of sintering temperature,BCNO changes from tubular structure of micron size to sheet structure.BCNO luminescent material exhibits 598 nm orange emission under the excitation of 315 nm.When the sintering temperature reaches 700 ^oC,the fluorescence intensity of BCNO luminescent materials reaches the maximum,and the quantum yield can reach 75%.Secondly,a series of BCNO phosphor was synthesized by porous melamine sponge,boric acid and urea in lower temperature and in a shorter time.The results of XRD analysis show that BCNO luminescent materials composed of h-BN and B₂O₃.Fluorescence spectroscopy show that BCNO has a yellow-green emission band with a center width of 567 nm,corresponding to the excitation wavelength of 347 nm,and the quantum efficiency is close to 86%.The emission decay curves indicated that there are two main emission centers corresponding to the redundant carbon and oxygen elements.The redundant carbon and oxygen elements are the main reasons for the decay process.Finally,the best luminescent material BCNO（24）synthesized by using melamine sponge as template.To explore the recognition of some inorganic metal cations(Al³⁺、Cr³⁺、Cr⁶⁺、Mn²⁺、Fe³⁺、Co²⁺、Ni²⁺、Cu²⁺、Zn²⁺、Cd²⁺).Physical grinding experiments show that BCNO（24）luminescent materials have obvious recognition effect on Ni²⁺、Cr⁶⁺and other metal ions.BCNO（24）/PVA composite film was prepared in order to reduce the influence of the color of metal ion salts.The results show that BCNO（24）/PVA composite membrane has good selectivity for Cr⁶⁺ions and the detection concentration is 10^-5 mol/L.