TY - JOUR
T1 - Zinc phthalocyanine-graphene hybrid material for energy conversion
T2 - Synthesis, characterization, photophysics, and photoelectrochemical cell preparation
AU - Karousis, Nikolaos
AU - Ortiz, Javier
AU - Ohkubo, Kei
AU - Hasobe, Taku
AU - Fukuzumi, Shunichi
AU - Sastre-Santos, Ángela
AU - Tagmatarchis, Nikos
PY - 2012/9/27
Y1 - 2012/9/27
N2 - 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 •+, yielding the charge-separated state ZnPc •+-graphene •-. Finally, the ZnPc-graphene hybrid material was integrated into a photoactive electrode of an optical transparent electrode (OTE) cast with nanostructured SnO 2 films (OTE/SnO 2), which exhibited stable and reproducible photocurrent responses, and the incident photon-to-current conversion efficiency was determined.
AB - 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 •+, yielding the charge-separated state ZnPc •+-graphene •-. Finally, the ZnPc-graphene hybrid material was integrated into a photoactive electrode of an optical transparent electrode (OTE) cast with nanostructured SnO 2 films (OTE/SnO 2), which exhibited stable and reproducible photocurrent responses, and the incident photon-to-current conversion efficiency was determined.
UR - http://www.scopus.com/inward/record.url?scp=84866869835&partnerID=8YFLogxK
U2 - 10.1021/jp305783v
DO - 10.1021/jp305783v
M3 - Article
AN - SCOPUS:84866869835
SN - 1932-7447
VL - 116
SP - 20564
EP - 20573
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 38
ER -