Zinc Phthalocyanine-Graphene Hybrid Material for Energy Conversion: Synthesis, Characterization, Photophysics, and Photoelectrochemical Cell Preparation
Zinc Phthalocyanine-Graphene Hybrid Material for Energy Conversion: Synthesis, Characterization, Photophysics, and Photoelectrochemical Cell Preparation
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DOI：
10.1021/jp305783v
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发表时间：
2012-09-27
影响因子：
3.7
通讯作者：
Tagmatarchis, Nikos
中科院分区：
文献类型：
--
作者：
Karousis, Nikolaos;Ortiz, Javier;Tagmatarchis, Nikos
在o-二氯苯（o-DCB）中完成尖端超声后石墨烯脱落。然后将（2-氨基乙氧基）（三叔丁基）酞菁锌（ZnPc）共价接枝到剥离的石墨烯片上。新形成的znpc -石墨烯杂化材料可以在常见的有机溶剂中溶解数周，没有任何沉淀。各种光谱技术的应用验证了ZnPc-石墨烯杂化材料的成功形成，而热重分析显示了ZnPc在石墨烯上的负载量。利用原子力显微镜（AFM）和透射电镜（TEM）分析了石墨烯薄片的形态特征，并对其剥落进行了研究。ZnPc在ZnPc-石墨烯杂化材料中的高效荧光猝灭表明，从光激发的ZnPc到脱落的石墨烯发生了光诱导事件。利用飞秒瞬态吸收光谱分析了光致电子转移动力学，揭示了ZnPc中心点+等瞬态物质的形成，产生了电荷分离态ZnPc中心点+-石墨烯（中心点-）。最后，将znpc -石墨烯杂化材料集成到由纳米结构SnO2薄膜（OTE/SnO2）浇铸的光学透明电极（OTE）的光活性电极中，该电极具有稳定且可重现的光电流响应，并测定了入射光子到电流的转换效率。
Graphene exfoliation upon tip sonication in o-dichlorobenzene (o-DCB) was accomplished. Covalent grafting of (2-aminoethoxy)(tri-tert-butyl) zinc phthalocyanine (ZnPc) to exfoliated graphene sheets was then achieved. The newly formed ZnPc-graphene hybrid material was found to be soluble in common organic solvents without any precipitation for several weeks. Application of diverse spectroscopic techniques verified the successful formation of the ZnPc-graphene hybrid material, while thermogravimetric analysis revealed the amount of ZnPc loading onto graphene. Microscopy analysis based on AFM and TEM was applied to probe the morphological characteristics and to investigate the exfoliation of graphene sheets. Efficient fluorescence quenching of ZnPc in the ZnPc-graphene hybrid material suggested that photoinduced events occur from the photoexcited ZnPc to exfoliated graphene. The dynamics of the photoinduced electron transfer was evaluated by femtosecond transient absorption spectroscopy, thus revealing the formation of transient species such as ZnPc center dot+, yielding the charge-separated state ZnPc center dot+-graphene(center dot-). Finally, the ZnPc-graphene hybrid material was integrated into a photoactive electrode of an optical transparent electrode (OTE) cast with nanostructured SnO2 films (OTE/SnO2), which exhibited stable and reproducible photocurrent responses, and the incident photon-to-current conversion efficiency was determined.