Zn2+/GaOOH纳米线的制备、表征与荧光性能

Preparation, characterization and photoluminescence of Zn2+/GaOOH nanowires

  • 摘要: 羟基氧化镓(GaOOH)是一类宽带隙的半导体材料,在光催化降解有机染料、甲醇燃料电池、锂离子电池和生物光学成像方面有着潜在的应用前景。本研究以乙二胺四乙酸二钠(Na2Y)为模板剂,选取醋酸锌和硝酸镓为反应源,在简便易操作的水热条件下制备了Zn2+/GaOOH纳米线。采用XRD、SEM、HRTEM、EDS对材料进行了物相、成分、形貌与微结构表征。所制备的Zn2+/GaOOH纳米线长度达数十微米、直径约为100 nm,粗细均匀;Zn2+/GaOOH晶体呈现单晶的特性,纳米线沿<110>晶向生长。反应源及其摩尔量强烈地影响着产物的物相和形貌。当控制硝酸镓为1.5 mmol不变,Zn(Ac)2为1.0 mmol,Na2Y为0.5 mmol时,生成ZnGa2O4;Na2Y为1.0~1.7 mmol时,生成Zn2+/GaOOH纳米线。改变Zn(Ac)2为2.0 mmol,当Na2Y 为1.5 mmol时,得到尖晶石型结构的ZnGa2O4。详细探究了Zn∶Ga∶Y摩尔量比例影响产物的物相和形貌的规律,结果显示当控制Zn∶Ga∶Y=2∶3∶3时,可以得到相纯均一的Zn2+/GaOOH纳米线。荧光测试表明,紫外光照射Zn2+/GaOOH纳米线,在蓝绿光区域的469 nm 波长处有很强的发射峰,归因于阴离子空位缺陷激发重组后的发射。随着激发波长蓝移,其发射峰强度增加,214 nm时强度最大。相对于ZnGa2O4纳米颗粒而言,在226 nm激发波长下,Zn2+/GaOOH纳米线在469 nm 波长处有更高的发射峰强度,Zn2+/GaOOH纳米线比ZnGa2O4纳米颗粒具有更好的荧光性能。

     

    Abstract: Gallium oxide hydroxide (GaOOH) is a kind of semiconductor material with broad-band gap and has extensive potential applications in the fields such as photocatalytic degradation of organic dyes, direct methanol fuel cell, lithium ion battery, bioluminescent imaging and so on. In our study, Zn2+/GaOOH nanowires have been synthesized via a facile and controllable hydrothermal method with zinc acetate and gallium nitrate as reactants and ethylenediaminetetraacetic acid disodium salt (Na2Y) as template. The products were characterized by XRD、SEM、HRTEM and EDS techniques. The length of the as-prepared uniform Zn2+/GaOOH nanowires is up to several micrometers and the diameter is about 100 nm. Zn2+/GaOOH is single crystalline and grew along crystalline direction <110>. The phase and morphology of Zn2+/GaOOH are affected by reactants and their amounts. Keeping the reactant amount of 1.5 mmol gallium nitrate stand, Zn2+/GaOOH nanowires form with 1.0 mmol zinc acetate and 1.0-1.7 mmol Na2Y, while spinel ZnGa2O4 nanoparticles obtain with 0.5 mmol Na2Y. When the reactant amount of zinc acetate is changed to 2.0 mmol, only spinel ZnGa2O4 nanoparticles can be obtained with the reactant amount of 1.5 mmol gallium nitrate. The detail of the effects of the products by Zn∶Ga∶Y mole ratios on the phase and morphology was studied, showing the forming condition of phase-pure and uniform Zn2+/GaOOH nanowires with the Zn∶Ga∶Y mole ratio of 2∶3∶3. The result of photoluminescence determination shows that Zn2+/GaOOH nanowires exhibit strong PL emission in the blue-green wavelength range, attribute to the recombination of the defect-related excitations through an excitation-excitation collision process. The strongest PL emission is at 469 nm with the excitaton of 214 nm. The intensity of the emission peak at 469 nm rises with the blue-transiton of excitation wavelength. Zn2+/GaOOH nanowires show higher intensity of the emission peak at 469 nm by the excitation wavelength of 226 nm, accompany with ZnGa2O4 nanoparticles, indicating more excellent photoluminescence performance.

     

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