Bhattacharya Sudeshna, Mandal Gopa, Dutta Mrinal, Basak Durga, Ganguly Tapan
Department of Spectroscopy, Indian Association for the Cultivation of Science, Jadavpur Kolkata 700032, India.
J Nanosci Nanotechnol. 2011 Sep;11(9):7735-43. doi: 10.1166/jnn.2011.5115.
The steady state and time resolved spectroscopic studies reveal that two xanthene dyes Rhodamine 6G (R6G) and Rhodamine B (RB), used in the present investigations, form ground state hydrogen -bonded complexes with meso-tetrakis(4-carboxyphenyl) porphyrin (TCPP). However, it is apparent that upon photoexcitation the H-bonding complexes formed in the ground state decompose into the individual reacting components. This presumption was confirmed from the observation of the presence of only static quenching mode in the steady state fluorescence of the dyes in presence of porphyrin. The photoelectrochemical properties of the free dyes and the mixtures of each dye with porphyrin are investigated by measuring incident photon-to-current conversion efficiency (IPCE) using ZnO electrode and also with TiO2 electrode. It is seen that Rhodamine B-porphyrin mixture has attained maximum IPCE among the four samples studied at approximately 550 nm using ZnO electrode. Using TiO2 electrode, slight improvement in the value of IPCE was found for the same mixture. Therefore Rhodamine B-porphyrin mixture may act as a good sensitizer for converting solar energy to electrical energy.
稳态和时间分辨光谱研究表明，本研究中使用的两种呫吨染料罗丹明6G（R6G）和罗丹明B（RB）与中位四（4-羧基苯基）卟啉（TCPP）形成基态氢键复合物。然而，很明显，在光激发后，基态形成的氢键复合物分解为单个反应组分。卟啉存在时染料稳态荧光中仅存在静态猝灭模式的观察结果证实了这一推测。通过使用ZnO电极以及TiO2电极测量入射光子-电流转换效率（IPCE），研究了游离染料以及每种染料与卟啉混合物的光电化学性质。可以看出，在使用ZnO电极研究的四个样品中，罗丹明B-卟啉混合物在约550nm处获得了最大IPCE。使用TiO2电极时，发现相同混合物的IPCE值略有提高。因此，罗丹明B-卟啉混合物可能是一种将太阳能转化为电能的良好敏化剂。
