微反应器策略实现γ-CuI的形貌调控

Microreactor Strategy for Morphology Modulation ofγ-CuI

γ-CuI较宽的能带空隙及较高的离子电导率等特点,使其在光能利用和超快闪烁材料领域有着广泛的应用。γ-CuI的形貌往往对其结构性质有重要的影响,精准地调控其形貌有很大的意义。因此,本文采用微反应法,通过控制不同NH_(3)·H_(2)O用量、Cu源、管内反应停留时间及合成温度等因素,结合SEM、XRD和FT-IR等测试手段,对不同合成条件下制备得到的γ-CuI的晶型与形貌进行了研究。并对传统液相沉淀法和微反应法制备的γ-CuI进行了比较。结果表明,当NH_(3)·H_(2)O使用量(C NH_(3)·H_(2)O/C N_(2)H_(4))为0.4、管内停留时间为10 s、反应温度为20℃的条件下达到90.5%的最高产率。其中,NH_(3)·H_(2)O的使用量对形貌的影响最大,当NH_(3)·H_(2)O的使用量为0.4时,合成了形貌均一的棒状γ-CuI。对比不同的铜源,除Cu(CH 3 COO)2·H 2 O制备得到棒状的γ-CuI,其余Cu源均主要生成颗粒状γ-CuI。增加管内时间则有助于棒状γ-CuI的形成,但进一步增长时间会导致样品在管内损失。此外,过高的反应温度会导致棒状γ-CuI逐渐向颗粒状γ-CuI转化。

Owing to its wide energy band gap,fast ionic conductivity at high temperatures,the ability to maintain a stable p-type conductivity at room temperature and poor spin-orbit splitting,γ-CuI is widely used in optical energy applications and ultrafast scintillation materials.The morphology ofγ-CuI is determined by its synthesis conditions.In this paper,γ-CuI with different morphology were synthesized by microreaction method through controlling different NH_(3)·H_(2)O dosage,Cu source,in-tube reaction residence time,and temperature in the reaction.The crystalline phase and morphology of theseγ-CuI were investigated by SEM,XRD and FT-IR.Theγ-CuI prepared by the traditional liquid phase precipitation method was taken as a comparison.The results show that,the highest yield of 90.5%is achieved when the amount of NH_(3)·H_(2)O used(C NH_(3)·H_(2)O/C N_(2)H_(4))is 0.4,the residence time in the tube is 10 s,and the reaction temperature is 20℃.Among them,the amount of NH_(3)·H_(2)O used(which has the greatest effect on the morphology)is 0.4,the rod-shapedγ-CuI with homogeneous morphology is synthesized.Comparing different Cu sources,except for Cu(CH 3 COO)2·H 2 O that is prepared to obtain the rod-shapedγ-CuI,all the remaining Cu sources mainly produce the granularγ-CuI.Increasing the in-tube time contribute to the rod-shapedγ-CuI CuI formation,but further increase time will lead to sample loss in the tube.In addition,too high reaction temperature will cause the gradual conversion of rodγ-CuI to granularγ-CuI.