沉积温度对多元醇法制备硫化镉薄膜的影响

CdS thin films were successfully deposited onto glass substrates for the first time by the polyol method using cadmium acetate, thiourea and diethylene glycol as the raw materials. The effects of the deposition tempera- ture from 120 to 200 ℃ in steps of 20 ℃on the structure, morphology and optical properties of the resultant films were investigated. It was found that the crystallinity was improved and the value of the surface average roughness was decreased with increasing the deposition temperature. The average grain sizes of the CdS thin films were 77.16 and 76.61 nm at 140 and 180 ℃, respectively. All samples showed excellent transmittance and the band gaps were found to reduce from 2.55 to 2.45 eV with the increase of the deposition temperature, which was attributed to the improvement of crystallinity.     

Preparation and photocatalytic activities of 3D flower-like CuO nanostructures

Hierarchical 3D flower-like CuO nanostructures on the Cu substrates were synthesized by a wet chemical method and subsequent heat treatment. The synthesis, structure and morphologies of obtained samples under different concentrations of Na₂S₂O₃ were investigated in detail and the possible growth mechanisms of the 3D flower-like CuO nanostructures were discussed. Na₂S₂O₃ plays a key role in the generation of the 3D flower-like CuO nanostructures. When the concentration of Na₂S₂O₃ is more than 0.4 mol/L, the 3D flower-like CuO nanostructures can be prepared on the Cu foils. The photocatalytic performances were studied by analyzing the degradation of methyl orange (MO) in aqueous solution in the presence of hydroxide water (H₂O₂). The 3D flower-like CuO nanostructures exhibit higher photocatalytic activity (96.2% degradation rate) than commercial CuO particles (36.3% degradation rate). The origin of the higher photocatalytic activity of the 3D flower-like CuO nanostructures was also discussed.     

合成ZnO纳米阵列及刺突状CuO/ZnO异质结

采用低温水热法在掺氟SnO₂ (FTO)导电玻璃表面制备ZnO纳米阵列, 研究了前驱体溶液浓度摩尔配比对ZnO纳米阵列形貌、光学性能及其生长机理的影响. 研究发现, 随着前驱体溶液浓度摩尔配比的增加, ZnO纳米阵列形貌及光学性能也随之变化. ZnO纳米阵列高度逐渐降低, ZnO纳米阵列直径和光学带隙值大体上出现先增大后降低的趋势. 而当前驱体溶液(Zn(NO₃)₂:环六亚甲基四胺(HMT, C₆H₁₂N₄))浓度摩尔配比为5:5时, 其光学禁带值(3.2 eV)接近于理论值. 结果显示制备ZnO纳米阵列的最优浓度摩尔配比为5:5. 随后选用最优浓度摩尔配比下制备的ZnO纳米阵列为基底, 通过一种两步溶液法成功在其表面制备刺突状CuO/ZnO异质结.从场发射扫描电镜(FE-SEM)结果中可以清楚看见, 大量的CuO纳米粒子沉积在ZnO纳米阵列表面形成刺突状异质结结构.研究发现该CuO/ZnO纳米异质结相对于纯ZnO纳米阵列在紫外光下光催化性能明显增加. 最后, 讨论了CuO/ZnO纳米异质结光催化机理.     

基于螺环结构桥连的固有微孔卟啉聚合物网络的制备与表征及其催化Knoevenagel缩合反应

通过5,10,15,20-四(4-羧基苯基)(TCPP)卟啉单体与含螺环结构的二胺单体(SpiroDA)的缩聚反应,实现了含螺环结构的卟啉基固有微孔材料的定向合成(PIM-Spiro)。同时在相同的工艺条件下,以对苯二胺(PPDA),4,4'-二氨基二苯醚(ODA)作为二胺单体分别制备了相应的聚酰胺(PA)网络材料。采用傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、热重分析(TG)、氮气吸附等分析测试手段对3种聚酰胺材料的网络结构和物理化学性能进行了表征。结果表明:螺环扭曲结构的引入可以有效提高微孔卟啉聚合物网络的比表面积,同时在溶剂中表现出很强的溶胀特性;所制备的聚酰胺网络材料中的卟啉基和酰胺键所含的高密度N—H键,赋予材料良好的碱性催化特性。     

紫色毛癣菌感染人头发的超微形态电镜观察

应用扫描电镜和透射电镜对紫色毛癣菌感染的头发进行超微形态结构的观察,了解紫色毛癣菌在感染头发后自身形态的变化以及对发干的破坏程度。结果表明：紫色毛癣菌在侵入人头发后主要寄生于毛干的毛皮质层,并呈现出不同的形态学特征。在感染初期紫色毛癣菌以菌丝样或竹节菌丝的形态寄生于毛干中,随着头发的生长菌丝逐渐断裂形成单个的圆形或柱状孢子,同时在形态转化的过程中,紫色毛癣菌对头发的破坏也逐渐加重。这提示紫色毛癣菌在感染人体头发后以有分隔的菌丝和竹节样孢子形式进行寄生繁殖。还观察到紫色毛癣菌形态转化时呈现自身菌体超微结构的改变,为进一步研究该菌的生物学特性提供了依据。