染料敏化二氧化钛-石墨烯杂化材料光催化水分解制氢

以曙红、石墨氧化物与二氧化钛(P25)为原料,利用水热法制备曙红敏化的二氧化钛-石墨烯杂化材料。通过X射线光电子能谱(XPS)考察了石墨氧化物(GO)以及染料敏化二氧化钛石墨烯杂化材料(T-G-EY)的C1s信号的变化,水热过程使石墨烯含氧官能团含量大幅度减少,透射电镜照片清晰地显示二氧化钛纳米颗粒均匀分散在石墨烯片层上。紫外-可见漫反射光谱(DRS)分析发现复合材料的带隙变窄,从P25的3.25 eV降低到2.75 eV,吸光范围明显向可见光区拓展,并存在曙红的特征吸收峰。从荧光光谱上明显看出复合材料发生了荧光猝灭现象,确认是石墨烯与二氧化钛之间及曙红与石墨烯之间存在一定的相互作用。T-G-EY在500 W氙灯照射下光解水制氢气的效率比P25提高了10.2倍。

Photocatalytic hydrogen evolution from water by dye-sensitized titania/graphene nanocomposite

Eosin Y(EY)dye sensitized nanocomposite of TiO₂ with graphene(T-G-EY)was prepared by hydrothermal process starting from EY,TiO₂(P25)and graphene oxide(GO).X-ray photoelectron spectroscopy(XPS)measurement showed dramatically decrease in the content of oxygen-containing functional groups due to the reduction of GO in the hydrothermal process.Transmission electron microscopy(TEM)observation illustrated that the graphene in T-G-EY nanocomposite was relatively uniformly covered and anchored by P25.The nanocomposite had a band gap of 2.75 eV,which was narrower than that of P25(3.25 eV)and light absorption was extended to the visible light region.Photoluminescent quenching was also observed in the T-G-EY nanocomposite,illustrating the interactions between components.The photocatalytic activity of T-G-EY for hydrogen evolution from water under a 500 W xenon lamp irradiation was greatly enhanced than that of P25.