石墨烯-纳米二氧化钛复合材料的绿色制备及性能研究

Green preparation of graphene-nano TiO2 composites and study on their properties

以鳞片石墨为原料,胆酸钠为表面活性剂,采用物理法高速剪切制备石墨烯(GR)。以自制的石墨烯与纳米二氧化钛(TiO2)为原料,采用简单搅拌、超声处理、水热反应3种不同的方法制备石墨烯-二氧化钛(GR-TiO2)复合材料。采用拉曼光谱、扫描电镜、紫外可见吸收光谱、傅里叶变换红外光谱对样品进行分析表征。模拟紫外光和太阳光,分别研究复合材料对甲基橙的降解能力。结果表明,通过高速剪切制备的石墨烯的质量浓度为0.059 mg/m L,缺陷较小且层数大部分为2层。3种复合材料相比,在紫外光下GR-TiO2(超声)的效果最好,比TiO2提高23.08%;在太阳光下GR-TiO2(水热)的效果最好,比TiO2提高42.67%。与传统方法相比,直接用石墨烯制备GR-TiO2复合材料的方法简单且绿色环保。

Graphene(GR)is prepared by high-speed physical shearing method using flake graphite as raw material and sodium cholate as surfactant.Graphene-titanium dioxide(GR-TiO2)composites are prepared from self-made graphene and nano-titanium dioxide(TiO2)using three different methods such as simple stirring,ultrasonication and hydrothermal reaction,respectively.The samples are characterized by Raman,scanning electron microscopy,UV-visible absorption spectroscopy and Fourier transform infrared spectroscopy.The degradation ability of the composite samples to methyl orange is studied through simulating ultraviolet light and sunlight,respectively.The results show that the concentration of the graphene prepared by high-speed shearing method is 0.059 mg·m L-1,the obtained graphene has few defects and exhibits 2 layers mostly.Among three composite materials prepared by different methods,GR-TiO2 prepared by ultrasonication has the best effect under ultraviolet light,which is 23.08%higher than TiO2;and GR-TiO2(hydrothermal)shows the best degradation effect to methyl orange under sunlight,which is 42.67%higher than that by TiO2.Compared with the conventional method,the direct use of graphene to prepare GR-TiO2 composites is simple and environmentally friendly.