α-ZnS:Mn纳米荧光粉热分解法制备及其发光性能

以Zn(NO3)2·6H2O(硝酸锌)、Mn(NO3)2·3H2O(硝酸锰)和Ddtc·3H2O(二乙基二硫代氨基甲酸钠)为原料,制得含硫金属有机配合物。将含硫金属有机配合物在不同反应溶液中,于200℃进行热解,制备了ZnS∶Mn纳米荧光粉。结果表明,样品为六方晶系的高温相α-ZnS∶Mn。在二甘醇加5mL油酸反应溶液中制得的ZnS∶Mn纳米材料紫外吸收峰最高,粒径更小。在323nm光激发下,看到了Mn2+的橘黄色发射峰(585nm)和ZnS的蓝色发射峰(450nm),随着Mn2+离子掺杂量增加,585nm发光强度先增加后减小,掺杂量为4%时达到最大值,而450nm发光强度变化与此相反。     

ZnS/ZnO/rGO复合材料的制备及其光催化性能研究

以醋酸锌、硫化钠为原料,聚乙烯吡咯烷酮(PVP)为改性剂,采用一步合成法制备了β-ZnS,再通过焙烧制备ZnS/ZnO异质结材料,然后加入一定量氧化石墨烯(GO)利用水热法成功制备了ZnS/ZnO/rGO复合材料。结果表明,在水热时间16 h、水热温度140℃、GO∶(ZnS/ZnO)质量比20%的条件下,所制备的ZnS/ZnO/rGO复合材料在可见光光照120 min内对亚甲基蓝的降解率可达80.3%。     

声化学法低温制备α-ZnS纳米粒子及其反应机理

以无水氯化锌,硫代乙酰胺为原料,采用声化学法在低温成功制备了六方纤锌矿相硫化锌(α-ZnS)纳米晶,并对其反应机理作了初步探讨.采用X射线粉末衍射(XRD),示差扫描量热分析(DSC),透射电子显微镜(TEM)以及选区电子衍射分析(SAED)对所制得的纳米粉末进行了表征.结果表明:所制备ZnS为六方纤锌矿结构,粒子尺寸大约在20～30 nm.合成ZnS纳米粒子的形貌接近于球形,选区电子衍射图中三个衍射环分别对应于α-ZnS的(002)、(110)和(112)晶面.在超声辐射下,反应溶液体系首先生成具有六方结构的碱式氯化锌(Zn_5(OH)_8Cl_2·H_2O),为α-ZnS纳米粒子的生长提供了很好的模板.     

Controllable biosynthesis and characterization of α-ZnS and β-ZnS quantum dots: Comparing their optical properties

The controllable biosynthesis of α-ZnS and β-ZnS quantum dots by Clostridiaceae sp. using different concentration of hydroxypropyl starch as dispersant are demonstrated. The structure and properties are characterized by XRD, TEM, HRTEM, UV–Vis and fluorescence spectra, and so on. The results indicate that the α-ZnS quantum dots with wurtzite structure and diameter of 8±2 nm were attained under low dose of hydroxypropyl starch, while high dose obtained the β-ZnS quantum dots with sphalerite structure and diameter of 4±1 nm. The UV–Vis absorption of β-ZnS quantum dots have an evident red shift compared with α-ZnS quantum dots, and the as-biosynthesized β-ZnS quantum dots have a stronger fluorescence activity than α-ZnS quantum dots. This work displays a simple biosynthetic method to control the crystal structure and particle size of metal sulfide nanoparticles under mild conditions.