镍负载二氧化钛/PEI/石墨烯纳米复合催化剂的制备与研究

Preparation and Properties Research of Ni-load TiO2/ PEI/Graphene Nano-composite Catalyst

摘要:

首先采用改进的Hummers法制备了氧化石墨烯(GO)，再以聚乙烯亚胺(PEI)修饰的氧化石墨烯为载体，并以硫酸钛和氯化镍为前驱体，利用水热法在180 ℃下以PEI为交联剂制得镍负载的TiO2/PEI/石墨烯纳米复合催化剂。通过紫外可见分光光度计(UV-vis)、傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)等测试手段对催化剂进行了表征。结果表明，Ni-TiO2/PEI/RGO纳米复合催化剂中镍负载TiO2纳米粒子与石墨烯能够均匀复合，并具有较小的晶粒尺寸。以对硝基苯酚(4-NP)为降解目标物，考察了该催化剂在NaBH4存在下还原4-NP的催化活性。结果表明，镍负载的TiO2/PEI/石墨烯纳米复合催化剂具有良好的重复催化活性，其降解率为98%，催化剂重复使用10次后，降解率仍能保持90%以上。

Abstract:

We first prepared graphene oxide (GO) by an improved Hummers method, and then Ni-loaded TiO2/PEI/RGO nanocomposite catalyst was fabricated with the PEI modified graphene oxide suspension, NiCl2 and Ti(SO4)2 precursor through a hydrothermal method at 180 °C by using PEI as a linker among the components. The prepared samples were characterized by UV-visible absorption spectrum (UV-vis), Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that Ni-loaded TiO2 nanoparticles were dispersed uniformly on the surface of graphene sheets and had smaller particle size. The nanocomposites were used as catalysts to remove 4-nitrophenol from wastewater with the help of NaBH4. The results indicated that this catalyst exhibited superior catalytic activity toward the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with a high degradation efficiency above 98 % in aqueous solution, and the catalytic activity was still feasible even over ten cycles.