Synthesis And Properties Of Porphyrin Spiral Polymers

The construction of supramolecular spiral polymers can control the highly ordered arrangement of dyes,which is expected to solve the problems about energy quenching and electron recombination caused by the narrow absorption range of dyes and the random aggregation of dyes in traditional dye-sensitized solar cells(DSSCs).In this paper,a series of Tx dyes with different anchoring groups were designed and synthesized and the structural and optical properties of the polymers were studied.Additionally,the polymer with a pyridine group as the anchoring group were introduced in DSSC to investigate the photoelectronic properties.Two porphyrin-based poly(isocyanide)with different anchoring groups were synthesized by introducing porphyrin derivatives with different substituents to the backbones of poly(isocyanide),which were modified by the chiral amino acid.They were meso-position unsubstituted porphyrin-based poly(isocyanide)T0 and meso-position-substituted porphyrin-based poly(isocyanide)T1.The optical properties of T0 without the anchoring group and T1 with the methyl acrylate group at meso position were studied by UV-visible absorption spectroscopy and it was presumed that the polymers prossessed helix structures.However,the hydrolysis reaction of T1 showed that it was difficult to obtain a complete hydrolysis product even under the mild reaction conditions.Then,meso-pyridine-substituted porphyrin-based poly(isocyanide)T5 was synthesized.The structural and optical properties of T5 were studied by UV-visible spectroscopy,CD chromatography,and AFM and It was also introduced into DSSCs.The results of photoelectric performance research showed that the introduction of helical structure not only enhanced J_sc by increasing the amount of dyes adsorption,but also enhanced V_oc by reducing the recombination between elecyrons in the conduction band of Ti O₂ and electrolytes.Finally,the photoelectric conversion efficiency of DSSCs with T5 was effectively improved.