Department of Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India.
ACS Appl Mater Interfaces. 2012 Dec;4(12):7027-35. doi: 10.1021/am302288m. Epub 2012 Dec 7.
Light-harvesting nanohybrids (LHNs) are systems composed of an inorganic nanostructure associated with an organic pigment that have been exploited to improve the light-harvesting performance over individual components. The present study is focused on developing a potential LHN, attained by the functionalization of dense arrays of ZnO nanorods (NRs) with a biologically important organic pigment hematoporphyrin (HP), which is an integral part of red blood cells (hemoglobin). Application of spectroscopic techniques, namely, Fourier transform infrared spectroscopy (FTIR) and Raman scattering, confirm successful monodentate binding of HP carboxylic groups to Zn(2+) located at the surface of ZnO NRs. Picosecond-resolved fluorescence studies on the resulting HP-ZnO nanohybrid show efficient electron migration from photoexcited HP to the host ZnO NRs. This essential photoinduced event activates the LHN under sunlight, which ultimately leads to the realization of visible-light photocatalysis (VLP) of a model contaminant Methylene Blue (MB) in aqueous solution. A control experiment in an inert gas atmosphere clearly reveals that the photocatalytic activity is influenced by the formation of reactive oxygen species (ROS) in the media. Furthermore, the stable LHNs prepared by optimized dye loading have also been used as an active layer in dye-sensitized solar cells (DSSCs). We believe these promising LHNs to find their dual applications in organic electronics and for the treatment of contaminant wastewater.
光捕获纳米杂化材料（LHNs）是由与有机颜料结合的无机纳米结构组成的系统，已经被开发用于提高光捕获性能超过单个组件。本研究的重点是开发一种潜在的 LHNs，通过用生物上重要的有机颜料血卟啉（HP）功能化致密的 ZnO 纳米棒（NRs）阵列来实现，HP 是红细胞（血红蛋白）的组成部分。应用光谱技术，即傅里叶变换红外光谱（FTIR）和拉曼散射，证实 HP 羧酸基团成功地与位于 ZnO NRs 表面的 Zn(2+) 发生单齿结合。对所得 HP-ZnO 纳米杂化物的皮秒分辨荧光研究表明，从光激发的 HP 到主体 ZnO NRs 的电子迁移是有效的。这种基本的光诱导事件在阳光下激活 LHNs，最终导致模型污染物亚甲基蓝（MB）在水溶液中的可见光光催化（VLP）的实现。在惰性气体气氛中的对照实验清楚地表明，光催化活性受介质中活性氧物种（ROS）形成的影响。此外，通过优化染料负载制备的稳定 LHNs 也已被用作染料敏化太阳能电池（DSSC）的活性层。我们相信这些有前途的 LHNs 将在有机电子学和处理污染物废水方面找到双重应用。
