Preparation Of Ruthenium Complexes,cobalt Complexes And Their Photocatalytic Performances For Hydrogen Production By Splitting Water

Visible light-driven water splitting into hydrogen as a clean and sustainable hydrogen production method has attracted more and more attentions of scientists.In this article,we built two photocatalytic hydrogen production system:based on the bipyridine ruthenium complexes sensitized titanium dioxide heterogeneous photocatalytic hydrogen production system and a cobalt-based catalyst homogeneous photocatalytic hydrogen production system.Two bipyridine ruthenium complexes(PS1, PS2) were synthesized and characterized by MS, elemental analysis, IR, NMR, UV-visible spectrum and cyclic voltammogram. Two bipyridine ruthenium complexes were sensitized on Pt-Ti O2 as composite photosensitive catalyst to build heterogeneous photocatalytic hydrogen production system in water, ascorbic acid used as an electron donor. Under the optimal condition, it showed that the maximum cumulative hydrogen production was 375.8μmol and the maximum rate of hydrogen evolution was 11903.3 μmol/g/h over 5h irradiation in the water system with PS1(20mg) sensitized on Pt-Ti O2 as composite photosensitive catalyst, ascorbic acid(1.0g) as sacrificial electron donor, p H=5.3. The cycle experiment showed the long-term stability of the composite photosensitive catalyst. The reason of reaction system deactivation speculated that photosensitive ruthenium complex dye desorption from the surface of Ti O2.Three cobalt-based photocatalyst(C1,C2,C3) were synthesized and characterized by IR, NMR, single crystal diffraction, UV-visible spectroscopy and cyclic voltammetry. The cobalt complex(C1,C2,C3) were used as photo-catalyst to build photocatalytic H2 production homogeneous system with Eosin Y dye(EY2-) as the photosensitizer, TEA or TEOA as electron donor, acetonitrile / water mixed solvent as solvent. Under the optimal condition([Cat.] 2×10-5M、EY2- 1 ×10-4M、10%TEA,v/v、p H=10.0、Me CN/H2O=1:1,v/v), it showed that the maximum amount of H2 generated for the cobalt complex C1 was 352 TON(vs. catalyst) after 3 hours irradiation of visible light.