TiO_(2)/石墨烯夹层结构复合材料的制备及光催化性能

Preparation and photocatalytic properties TiO_(2)/graphene nanocomposites with sandwich structure

以氧化石墨烯(GO)、1,12-二氨基十二烷(C_(12)H_(28)N_(2))、TiO_(2)溶胶为原料,通过预插层-离子交换-煅烧法制备TiO_(2)/石墨烯夹层结构纳米复合材料。采用XRD、Raman、FTIR、TEM、TG、UV-Vis和PL对TiO_(2)/石墨烯夹层结构纳米复合材料进行表征,并研究不同TiO_(2)含量的TiO_(2)/石墨烯纳米复合材料对环丙沙星(CIP)的光催化降解性能。在煅烧过程中,TiO_(2)的晶化和GO的还原同时进行。根据XRD和FTIR结果推断,TiO_(2)纳米颗粒在石墨烯层间原位生成,并通过化学键固定在石墨烯上,形成了石墨烯/TiO_(2)/石墨烯夹层结构。当TiO_(2)的质量分数为65.5wt%时,TiO_(2)/石墨烯复合材料表现出对环丙沙星最佳的光催化活性,150 min光照后降解率为90%高于纯TiO_(2)(28%、150 min)。这主要是特殊的夹层结构增强了光生电子-空穴分离。在光催化降解CIP的过程中,光生空穴和超氧自由基是主要的活性物质。此外,TiO_(2)/石墨烯纳米复合材料具有较好的光稳定性和结构稳定性,在环境净化方面具有潜在的应用前景。

TiO_(2)/graphene nanocomposites were synthesized from graphene oxide(GO),C_(12)H_(28)N_(2) and TiO_(2) sol by three-step method as follows:Dodecanediamine pre-intercalating,ion exchange,and interlayer in-situ formation of TiO_(2) by calcined.The properties and structures of TiO_(2)/graphene nanocomposites with sandwich structure were characterized by XRD,Raman,FTIR,TEM,TG,UV-Vis and PL.The photocatalytic degradation performance of TiO_(2)/graphene composites prepared with different amounts of TiO_(2) were investigated.The crystallization of TiO_(2) and the reduction of GO were significantly increased simultaneously during calcination.According to XRD and FTIR results,TiO_(2) nanoparticles have formed in situ between the interlayer of graphene and anchored on graphene with chemically-bonded.Therefore,it can be concluded that the TiO_(2)/graphene nanocomposites with sandwich structure are prepared successfully.TiO_(2)/graphene composites show the best photocatalytic degradation of ciprofloxacin(CIP)when the mass fraction of TiO_(2) is 65.5 wt%,and the degradation rate reaches 90%after 150 min under visible light irradiation,which is higher than pure TiO_(2) nanoparticles(28%,150 min).It can be mainly attributed to the special sandwich structure with enhanced photoinduced electron-hole separation.The photocatalyst stability test shows that TiO_(2)/graphene nanocomposites possess high photostability and structure stability for potential practical applications in environmental purification.