LaNiO3/石墨烯复合薄膜的制备及光催化性能

采用改进的Hummer法制备出薄层石墨烯材料,采用溶胶-凝胶法结合旋转涂膜技术以玻璃基底制备出石墨烯基LaNiO3复合薄膜。采用X射线衍射(XRD)仪,透射电镜(TEM),扫描电镜(SEM),拉曼光谱,X射线衍射光电子能谱(XPS)、紫外-可见(UV-Vis)吸收光谱和荧光光谱(PL)等测试手段对复合薄膜进行表征。结果表明,晶粒粒径约为20 nm的LaNiO3较均匀地生长在了石墨烯片上。光催化性能研究表明,LaNiO3/石墨烯复合薄膜的光催化活性显著优于LaNiO3薄膜,当石墨烯的含量约为4%时,复合薄膜4 h内对酸性红的降解效率比LaNiO3薄膜提高了1倍。     

蒸吸氨系统氨耗高的原因及改进措施

氨碱法生产纯碱工艺中氨耗是衡量蒸吸氨系统运行好坏的重要标志,以实际生产中对氨耗高的分析和解决措施论述蒸吸氨系统的管理和改造等方面的技术问题。     

电泳沉积制备LaMnO_3/石墨烯薄膜及其光催化性能

采用电泳沉积技术在氧化铟锡(indium tin oxide,ITO)导电玻璃基底上制备出LaMnO3/石墨烯薄膜。通过扫描电子显微镜、透射电子显微镜、X射线衍射、Raman光谱、紫外-可见吸收光谱和荧光光谱等测试手段探讨了电场强度、溶液的浓度、沉积时间等参数对薄膜结构和表面形貌的影响。结果表明,晶粒粒径约为20nm的LaMnO3较均匀地生长在石墨烯片上,且复合膜的厚度受到电场强度、电泳时间和悬浮液浓度的共同作用。光催化性能研究表明,LaMnO3/石墨烯薄膜的光催化活性显著优于纯LaMnO3薄膜,且还原氧化石墨烯的含量为2%时,该薄膜的光催化性能最好,3h内对直接绿的脱色率达到了98.8%。     

Preparation of La MnO_3/graphene thin films and their photocatalytic activity

A novel photocatalyst of La MnO3/graphene thin films with the perovskite-type was synthesized by sol-gel process assisted with spin-coating methods on glass substrates.The prepared samples were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), Brumauer-Emmett-Teller(BET) surface area analyzer, X-ray photoelectron spectroscopy(XPS) and UV-vis diffuse reflectance spectroscopy.Results showed that after the introduction of graphene, the perovskite structure was unchanged and the size of La MnO3 particles was about 22 nm, which uniformed growth in graphene sheet.Determination of contact angle indicated that the contact angle of glass substrate decreased and the hydrophilicity improved after treating with H2SO4 and APTES.The UV-Vis photocatalytic activity of the photocatalysts was evaluated by the degradation of diamine green B.La MnO3/graphene thin films had better photocatalytic ability than La MnO3 and Ti O2 films.The obtained k was 0.5627 and 0.3441 h–1 corresponding to La MnO3/graphene films and Ti O2 films, respectively.     

LaBO_3(B=Ni,Mn,Fe)/石墨烯复合薄膜的制备及光催化性能

为提高纳米钙钛矿型氧化物薄膜的光催化性能,应用改进的Hummer法制备出薄层石墨烯材料,并采用溶胶-凝胶法结合旋转涂膜技术在玻璃上制备出石墨烯基LaBO3(B=Ni,Mn,Fe)复合薄膜。利用XRD、FTIR、FESEM和TEM对薄膜样品的结构、晶粒尺寸及微观形貌进行表征,利用显微拉曼光谱仪测量制备出的石墨烯和薄膜样品在激光功率为400 mW时位于100?3 000 cm-1之内的拉曼光谱。将该复合薄膜作为光催化剂,研究石墨烯用量、不同B位元素对该复合薄膜光催化活性的影响。结果表明:复合薄膜的光催化活性显著优于纯钙钛矿薄膜的光催化活性;当石墨烯悬浮液的浓度为0.1 g/L,Ni作为B位阳离子时,该复合薄膜的光催化活性最好。