Organic nanotubes from two kinds of chiral molecules, R-di-2-naphthylprolinol （DNP） with an asymmetric carbon atom and R-（＋）-1,1＇-bi-2-naphthol dimethyl ether （BNDE） with the conformational asymmetry, were prepared by the immersing technique using porous alumina membranes as the template. It was found that the nanotubes from DNP with an asymmetric carbon atom presented the same chirality as the solution with slight red shift of the CD signals upon the formation of the nanotubes, while no well-defined chirality could be identified for the nanotubes from BNDE with the conformational asymmetry.
Photochromic polymolybdate-citric acid composite films were fabricated. It was found that after UV irradiation the composite films with different molar ratios of organic/inorganic components exhibited different colors. The UV-irradiated films showed dark blue, dark khaki and light sea green colors when the ratios were 1.0, 0.3 and 0.2, respectively. It was identified by Raman spectra that the polymolybdate species formed in the composite films after UV irradiation were sensitive to the ratios of the organic/inorganic components, thus resulting in the different colors of irradiated films. Citric acid played an important role during the photochromic process. Under UV light irradiation, it served as hole scavenger that suppresses the recombination of photogenerated electrons and holes to make the polymolybdates show UV light photochromism.
A new type quasi-solid state electrolyte was prepared by solidifying liquid electrolytes con- taining organic solvents (such as mixture of ethylene carbonate (EC) and propylene carbonate (PC), 3- methoxypropinitrile (NMP) and N-methyl-oxazolidin- one (NMO)) with comb-like molten salt type polymer, and was for the first time employed in dyesensitized solar cells (DSSCs). The optimal electrolyte compo- sition was obtained by regulating the polymer content in the electrolytes and optimizing performance data of the electrolytes and assembled cells, yielding a maximum conversion efficiency of 6.58% (AM 1.5, 100 mW·cm?2). Furthermore, the existence of this new type polymer in the electrolyte suppresses the evaporation of organic solvent and improves the sta- bility of the cells.
WANG MiaoYANG LeiZHOU XiaowenLIN YuanLI XuepingFENG ShujingXIAO Xurui
TiO2 nanotubes with diameters of 10 nm and lengths up to 600 nm were fabricated by directly using com-mercial TiO2 powders P25 as the precursors via sonica-tion-hydrothermal combination approach. TiO2 nanotubes were characterized by means of X-ray powder diffractometer (XRD), scanning electron microscope (SEM), selected area electron diffraction pattern (SAED) and transmission elec-tron microscope (TEM). The light scattering property of film electrodes modified with TiO2 nanotubes was studied and revealed that TiO2 nanotubes can be used as the light scat-tering centers to increase the light absorption in dye- sensi-tized solar cells. The TiO2 nanotubes film electrodes mixed with 10% small nanoparticles TiO2 had both strong light scattering property and fine mechanical characteristics, and this kind of electrodes can be used as electrodes in improving the conversion efficiencies of dye-sensitized solar cells.
Quasi-solid state dye-sensitized solar cells based on chemically crosslinking with backbone polymers of poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) or poly(vinylimidazole-co-acrylonitrile) (P(VIM-co- AN)) and diiodide compounds of I(CH2)6I or I(CH2CH2O)nCH2CH2I solidified EC/PC/KI/I2 gel electrolytes have been fabricated. The ionic conductivities and apparent diffusion coefficients of I3? of the electro- lytes and cell performances have been investigated. Providing chemically crosslinking points, pyridine or imidazole from the backbone polymers benefited the open circuit voltage and fill factor of the cells. Consequently, the overall energy conversion efficiencies of the quasi-solid DSSCs improved over 10% even near 20% from that of the liquid electrolyte before solidification. Besides, the employing of crosslinker I(CH2CH2O)nCH2CH2I showed higher electrolytic and cell characters than that of I(CH2)6I.
LI MinYuFENG ShuJingFANG ShiBiXlAO XuRuiLI XuePingZHOU XiaoWenLIN Yuan
The nanoparticles of a spirooxazine （SPO） and its photomerocyanine （PMC） were prepared through the reprecipitation method. Two distinct features were observed. One is that the decaying lifetime for PMC nanoparticles was 600 times of that for the dispersed molecules, and the other is that the fluorescence intensity of SPO nanoparticles was enhanced by 240 times of that of the dispersed monomer.
