Conjugated Molecular And Its Functionalized Platinum Nanocomposites: Synthesis, Light-harvesting And Photocatalysis

A series of architectural symmetry of porphyrins including porphyrin ring as the "core", polycyclic aromatic hydrocarbons for the "branch" through covalent or hydrogen bonds were synthesized. Substituting the fusedring aromatic compounds groups onto the porphyrin ring led the molecule to absorb over a broader range (200-700 nm) and to undergo efficient intramolecular/intermolecular energy transfer from the aromatic groups to the porphyrin ring. Porphyrins functionalized platinum nanocomposites were prepared, characterized and using the nanocomposites as photocatalyst for water splitting. Some corresponding researches were done as follows:(1) 5,10,15,20-tetrakis(4-(hydroxyl)phenyl) porphyrin (TPPH) bearing several naphthyl donor moieties 5,10,15,20-tetrakis(4-(naphthalen-1-ylmethoxy)phenyl) porphyrin (TPPNA-1~4), and a series of metalporohyrin (TPPNA-M M=Mg, Co, Cu, Zn) were synthesized and characterized by 1H NMR, FT-IR, UV-vis methods. The naphthylporphyrin functionalized platinum nanocomposites (Pt@TPPNA) have been successfully prepared with the alcohol reduction method and characterized with UV-vis, TEM, FTIR, XRD, Fluorescence spectroscopy and photo-electrochemical method, respectively. The diameter of the nanocomposites is range from 2-4 nm depending on the molar ratio of Pt to TPPNA. Under irradiation of UV-vis light, hydrogen was produced from photodecomposition of water using Pt@TPPNA nanocomposite as the catalyst in the presence of EDTA. The catalytic activity of Pt nanocomposite was influenced by the amount of catalyst, pH and the molar ratio of Pt/TPPNA.(2) 5,10,15,20-tetrakis(4-(hydroxyl)phenyl) porphyrin (TPPH) bearing several anthryl donor moieties 5,10,15,20-tetrakis (4-(anthracene-1-ylmethoxy)phenyl) porphyrin (TPPAN-1~4) was synthesized and characterized by 1H NMR, FT-IR, UV-vis methods. The anthrylporphyrin functionalized platinum nanocomposites (Pt@TPPAN) have been successfully prepared with the alcohol reduction method and characterized with UV-vis, TEM, FT-IR, XRD, Fluorescence spectroscopy and photo-electrochemical method, respectively. The diameter of the nanocomposites is range from 2-3 nm depending on the molar ratio of Pt to TPPAN. Under irradiation of UV-vis light, hydrogen was produced from photodecomposition of water using Pt@TPPAN nanocomposite as the catalyst in the presence of EDTA. The catalytic activity of Pt nanocomposite was influenced by the amount of catalyst, pH and the molar ratio of Pt/TPPAN.(3) Pyrenesulfonic acid (PSA) was synthesized by pyrene sulfonated and characterized by 1H NMR, FT-IR, UV-vis methods. To mimic photoinduced electron transfer processes in the natural photosynthetic reaction centre, constructing self-assembled pyrene-porphyrin conjugates (TPPH-PSA) held by hydrogen bonding will simplify the synthesis. The pyrene-porphyrin functionalized platinum nanocomposites (Pt@TPPH-PSA) have been successfully prepared with the alcohol reduction method and characterized with UV-vis, TEM, FT-IR, XRD, Fluorescence spectroscopy and photo-electrochemical method, respectively. Under irradiation of UV-vis light, hydrogen was produced from photodecomposition of water using Pt@TPPH-PSA nanocomposites as the catalyst in the presence of EDTA. The catalytic activity of Pt nanocomposite was influenced by the amount of catalyst, pH and the molar ratio of Pt/TPPH-PSA.