The Preparation And Catalytic Performance Of Photocathode With Hydrogenase Founctional Model Complexes

[Fe-Fe] hydrogenase in nature has excellent ability of catalyze proton to hydrogen. A lot of attentions have been focused on simulation of catalytic active center of nature hydrogenase [2Fe2S] structure for hydrogen generation in the photocatalytic systems in recent years.[2Fe2S] hydrogenase model complexes and cobalt complexes as founction model complexes of [Fe-Fe] hydrogenase for hydrogen prodroction are widely used in photocatalytic hydrogen generation systems.The photocatalytic systems above are under bad condition of acidic solvent or mixture of organic solvent and water, also electron sacrificial agent such as ascorbic acid are absolutely necessary for these homogeneous systems. If we can integrate water as electron donor into the hydrogen production systems, the progress will be a sustainable and ideal way for hydrogen evolution to solve the energy crisis and environmental pollution.In this thesis, we built a photocatalytic hydrogen production system consist of thioglycolic acid or cysteine as coupling agent attach to inorganic semiconductor CdS photosensitizer onto a p-type NiO semiconductor materials as photocathode and dimethylglyoxime cobalt complexes Com(dmgH)2Cl(Me-py) as catalyst, Pt as the counter electrode, Ag/AgCl as the reference electrode, sodium sulfate solution as electrolyte for water splitting by visible light driven in the PEC device. In the whole system, we didn’t add any additional electron sacrificial agent. Under visible light irradiation, the photocurrent intensity of the PEC device has an obvious increasing after dipping cobalt catalyst to the CdS-NiO photocathode and cysteine as coupling agent is better than thioglycolic acid for higher photocurrent increasment in the research which maybe caused by faster hole transportation from the excited CdS to NiO. The decay of photocurrent was observed and probably caused by the loose contact of the catalyst with the CdS-NiO electrode surface. Further investigations have to be made to increase the stability of the photocatalytic system.Furthermore, CdS as photosensitizer,[Fe-Fe] hydrogenase model complexes Fe2S2(CO)6as catalyst, triethanolamine as electron sacrifical agent to form a homogeneous catalytic systems for hydrogen production and hydrogen generated from the system was analysized at a gas chromatography device. As a result, the system has a significant increases amount of hydrogen after Fe2S2(CO)6catalyst was added in the systems which means electron from the conductive band of excited CdS can be transfered to Fe2S2(CO)6catalysts to catalyze proton to hydrogen. Under visible light driven, we also succeed achieve the decomposition of water in a PEC in which glycolic acid or cysteine as a coupling agent to link CdS to NiO as photocathode,[Fe-Fe] hydrogenase model complexes Fe2S2(CO)6is used as catalyst.