title: Probing the Highly Efficient Electron Transfer Dynamics between Zinc Protoporphyrin IX and Sodium Titanate Nanosheets.
abstract: Sodium titanate nanosheets (NaTiO2 NS) have been prepared by a new method and completely characterized by TEM, SEM, XRD, EDX, and XPS techniques. The sensitization of nanosheets is carried out with Zn protoporphyrin IX (ZnPPIX). The emission intensity of ZnPPIX is quenched by NaTiO2 NS, and the dominant process for this quenching has been attributed to the process of photoinduced electron injection from excited ZnPPIX to the nanosheets. Time resolved fluorescence measurement was used to elucidate the process of electron injection from the singlet state of ZnPPIX to the conduction band of NaTiO2 NS. Electron injection from the dye to the semiconductor is very fast (ket ≈ 10(11) s(-1)), much faster than previously reported rates. The large two-dimensional surface offered by the NaTiO2 NS for interaction with the dye and the favorable driving force for electron injection from ZnPPIX to NaTiO2 NS (ΔGinj = -0.66 V) are the two important factors responsible for such efficient electron injection. Thus, NaTiO2 NS can serve as an effective alternative to the use of TiO2 nanoparticles in dye sensitized solar cells (DSSCs).
authors.affiliation: Department of Chemistry, University of Kalyani , Kalyani 741235, Nadia, West Bengal, India.
authors.forename: Sudipta
authors.initials: S
authors.lastname: Biswas
authors.affiliation: Department of Inorganic and Physical Chemistry, Indian Institute of Science , Bangalore 560012, India.
authors.forename: Debdyuti
authors.initials: D
authors.lastname: Mukherjee
authors.affiliation: Department of Chemistry, University of Kalyani , Kalyani 741235, Nadia, West Bengal, India.
authors.forename: Swati
authors.initials: S
authors.lastname: De
authors.affiliation: National Centre for Ultrafast Processes, University of Madras, Taramani Campus , Taramani, Chennai 600113, Tamil Nadu, India.
authors.forename: Arunkumar
authors.initials: A
authors.lastname: Kathiravan