http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hasobe, Taku,Sakai, Hayato,Mase, Kentaro,Ohkubo, Kei,Fukuzumi, Shunichi American Chemical Society 2013 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.117 No.9
<P>An efficient visible light-induced hydrogen evolution system has been developed by using supramolecular porphyrin hexagonal nanocylinders that encapsulate Pt-colloids-deposited TiO<SUB>2</SUB> nanoparticles (Pt/TiO<SUB>2</SUB>) in the internal cavity. First, porphyrin nanocylinders structurally controlled by encapsulated Pt/TiO<SUB>2</SUB> are prepared via a solvent mixture technique. The bar-shaped structure composed of Pt/TiO<SUB>2</SUB> and zinc <I>meso</I>-tetra(4-pyridyl)porphyrin [ZnP(Py)<SUB>4</SUB>] is formed with the aid of a surfactant: cetyltrimethylammonium bromide (CTAB) in a DMF/H<SUB>2</SUB>O mixture solution [denoted as Pt/TiO<SUB>2</SUB>–ZnP(Py)<SUB>4</SUB> nanorods]. In scanning electron microscopy (SEM) measurements, ZnP(Py)<SUB>4</SUB> pristine hexagonal nanocylinder with a large hollow structure [denoted as ZnP(Py)<SUB>4</SUB> nanocylinder] was observed, whereas the hollow hole was completely closed in case of Pt/TiO<SUB>2</SUB>–ZnP(Py)<SUB>4</SUB> nanorods. X-ray diffraction (XRD) analyses also revealed that ZnP(Py)<SUB>4</SUB> alignment in the nanorod was based on the stacked-assemblies of ZnP(Py)<SUB>4</SUB> coordinated hexagonal formations. These results clearly indicate that Pt colloids-deposited TiO<SUB>2</SUB> nanoparticles (Pt/TiO<SUB>2</SUB>) were successfully encapsulated within a ZnP(Py)<SUB>4</SUB> hexagonal nanocylinder. Pt/TiO<SUB>2</SUB>–ZnP(Py)<SUB>4</SUB> also shows a broadened absorption in the visible region because of aggregation of ZnP(Py)<SUB>4</SUB>. Then, Pt/TiO<SUB>2</SUB>–ZnP(Py)<SUB>4</SUB> exhibited efficient hydrogen evolution under visible light irradiation, whereas no hydrogen was evolved in the case of Pt/TiO<SUB>2</SUB> without ZnP(Py)<SUB>4</SUB>. In addition, the hydrogen evolution efficiency of Pt/TiO<SUB>2</SUB>–ZnP(Py)<SUB>4</SUB> nanorods per unit weight of Pt was two orders magnitude greater than that of the nonencapsulated system: Pt/TiO<SUB>2</SUB> and ZnP(Py)<SUB>4</SUB> nanocylinder composites [Pt/TiO<SUB>2</SUB> + ZnP(Py)<SUB>4</SUB> composites]. Finally, the photodynamics of the excited state of Pt/TiO<SUB>2</SUB>–ZnP(Py)<SUB>4</SUB> nanorods was examined by femtosecond time-resolved transient absorption spectroscopy to clarify the photocatalytic mechanism.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2013/jpccck.2013.117.issue-9/jp400381h/production/images/medium/jp-2013-00381h_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp400381h'>ACS Electronic Supporting Info</A></P>
Hasobe, Taku,Saito, Kenji,Kamat, Prashant V.,Troiani, Vincent,Qiu, Hongjin,Solladié,, Nathalie,Kim, Kil Suk,Park, Jong Kang,Kim, Dongho,D'Souza, Francis,Fukuzumi, Shunichi Royal Society of Chemistry 2007 Journal of materials chemistry Vol.17 No.39
<P>We have constructed supramolecular solar cells composed of a series of porphyrin–peptide oligomers [porphyrin functionalized α-polypeptides, P(H<SUB>2</SUB>P)<SUB><I>n</I></SUB> or P(ZnP)<SUB><I>n</I></SUB> (<I>n</I> = 1, 2, 4, 8, 16)], and fullerenes assembled on a nanostructured SnO<SUB>2</SUB> electrode using an electrophoretic deposition method. Remarkable enhancement in the photoelectrochemical performance as well as the broader photoresponse in the visible and near-infrared regions is seen with increasing the number of porphyrin units in α-polypeptide structures. Formation of supramolecular clusters of porphyrins and fullerenes prepared in acetonitrile–toluene = 3 : 1 has been confirmed by transmission electron micrographs (TEM) and the absorption spectra. The highly colored composite clusters of porphyrin–peptide oligomers and fullerenes have been assembled as three-dimensional arrays onto nanostructured SnO<SUB>2</SUB> films using an electrophoretic deposition method. A high power conversion efficiency (<I>η</I>) of ∼1.6% and the maximum incident photon-to-photocurrent efficiency (IPCE = 56%) were attained using composite clusters of free base and zinc porphyrin–peptide hexadecamers [P(H<SUB>2</SUB>P)<SUB>16</SUB> and P(ZnP)<SUB>16</SUB>] with fullerenes, respectively. Femtosecond transient absorption and fluorescence measurements of porphyrin–fullerene composite films confirm improved electron-transfer properties with increasing number of porphyrins in a polypeptide unit. The formation of molecular assemblies between porphyrins and fullerenes with a polypeptide structure controls the electron-transfer efficiency in the supramolecular complexes, meeting the criteria required for efficient light energy conversion.</P> <P>Graphic Abstract</P><P>Solar cells capable of incident photon-to-current conversion efficiency of up to 56% were constructed using a series of porphyrin–peptide oligomers and fullerene assemblies. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b706678c'> </P>
Ohkubo, Kei,Kawashima, Yuki,Sakai, Hayato,Hasobe, Taku,Fukuzumi, Shunichi The Royal Society of Chemistry 2013 Chemical communications Vol.49 No.40
<P>A photoelectrochemical solar cell composed of supramolecular nanoclusters of lithium encapsulated fullerene and zinc sulphonated <I>meso</I>-tetraphenylporphyrin exhibits significant enhancement in the photoelectrochemical performance as compared with the reference system containing only a single component.</P> <P>Graphic Abstract</P><P>A photoelectrochemical solar cell composed of supramolecular nanoclusters of Li<SUP>+</SUP>@C<SUB>60</SUB> and ZnTPPS<SUP>4−</SUP> exhibits significant enhancement in the photoelectrochemical performance. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cc41187g'> </P>