氟化物纳米晶物相与形貌的水热控制合成

利用简便的螯合剂辅助水热方法制备了上转换基质六方相Na(Na0.5Y1.5)F6纳米晶,通过对pH的严格控制,成功实现了YF3、Na(Na0.5Y1.5)F6与Na0.41Y0.59F2.18的可控合成.产物的结构与微观形貌利用X射线衍射仪(XRD)与场发射扫描电镜(SEM)进行研究.结果表明pH值调节严重影响了氟化物的晶相及形貌:当pH为2时,产物为不规则块状晶体YF3;当pH=3,可以得到具有规则六角片状六方相Na(Na0.5Y1.5)F6纳米晶;随着pH值增加,所得样品由六方相的Na(Na0.5Y1.5)F6过渡到立方相Na0.41Y0.59F2.18.这种简单的相控制合成手段将有助于高效率上转换基质纳米晶的合成与潜在应用.

Controllable synthesis of the phase and morphology of fluoride nanocrystal by hydrothermal method

Up-conversion fluoride nanocrystal host material Na(Na0.5Y1.5)F6 were prepared via a facile hydrothermal route in the presence of the complexing agent EDTA.YF3,Na(Na0.5Y1.5)F6,and Na0.41Y0.59F2.18 were successfully synthesized by precisely pH manipulation.The structures and microcosmic morphology of the products under the different pH value were characterized via powder X-ray diffraction(XRD) and scanning electron microscopy(SEM).As a result,it reveals that the crystal phase and morphology of the fluoride can be controlled by the pH value: when the pH was 2,the products were anomalous nubbly crystal YF3;while the nanosheet were hexagonal-phase Na(Na0.5Y1.5)F6 with pH 2;with increasing of the pH,the samples were gradually transformed from hexagonal-phase Na(Na0.5Y1.5)F6 to cubic-phase Na0.41Y0.59F2.18.This facile route no doubt would promote the synthesis and potential application of high-efficiency up-conversion nanocrystal host material.