还原氧化石墨烯-TiO_2复合纳米材料制备与光催化性能

Preparation and photocatalytic properties of reduced graphene oxide-TiO_2 nanocomposites

利用新型碳材料还原氧化石墨稀对TiO_2进行改性,以期提高TiO_2的光催化活性.采用溶剂热法,以氧化石墨烯(GO)和钛酸四丁酯(Ti(OBu)4)为原料,成功制备了不同还原氧化石墨烯含量的RGO/TiO_2纳米复合材料.运用XRD、TEM、FT-IR和UV-vis等手段研究了复合材料的性质,同时以甲基橙(Methyl Orange,MO)为模型,评价了不同反应条件下制备的复合物的光催化性能,讨论了不同还原氧化石墨烯含量、催化时间等对复合物的光催化性能的影响.在甲基橙评价模型基础上,将制得的具有最佳光催化性能的RGO/TiO_2复合材料进行致病大肠杆菌的抗菌实验,以此来检验RGO/TiO_2纳米复合材料的抗菌效果.实验结果表明,采用溶剂热法在180℃下煅烧6h制得RGO/TiO_2纳米复合材料,锐钛矿相TiO_2通过C-O-Ti键均匀地分布在片层还原氧化石墨烯载体上.RGO/TiO_2复合材料对甲基橙溶液的降解率明显高于纯纳米TiO_2.当制备复合材料时GO的初始投加量为40mg时,制得的RGO/TiO_2复合材料对甲基橙的降解率达到50%.同时,该RGO/TiO_2纳米复合材料对致病大肠杆菌有明显的抗菌作用.

The photocatalytic degradation of organic compounds has attracted great attention.In this work,the photo-catalytic activity of TiO2 was significantly improved via modification with reduced graphene oxide（RGO）.The RGO/TiO2 nanocomposite,with varying RGO contents,was firstly fabricated by a solvothermal method.X-ray dif-fraction,high resolution transmission electron microscopy,Fourier transform infrared spectroscopy and UV-Vis spectroscopy were performed to characterize the structure and property of the as-prepared RGO/TiO2 nanocomposite.Based on a methyl orange model,the influence from different factors,including the RGO content and＆amp;nbsp;catalytic time,on photocatalytic activities as well as anti-Escherichia coli ability of the RGO/TiO2 nanocomposite, was investigated.The results show the binding between TiO2 nanostructures and RGO planes with C-O-Ti bonds within the nanocomposite after being calcined at 180＆#176;C for 6 h.The RGO/TiO2 nanocomposites consisting of an initial adding amount of 40 mg GO during synthesis process have a most enhanced photocatalytic degradation efficiency of as high as 50%.This might be due to the great adsorptivity of dyes,extended light absorption range and efficient charge separation properties.Also,a much improved anti-Escherichia coli ability of 93% was achieved by the same RGO/TiO2 nanocomposites.This work provides a new approach for the fabrication of TiO2-based nano-composite as visible-light photocatalyst of high performance,and facilitates its application for photocatalytic degradation of organic compounds.