Synthesis of Biomimetic Dithiolate-Bridged Osmium-Sulfur Clusters and Their Applications for Photocatalytic Hydrogen Production

• Main Authors: Wu, Hsin-Hua, 吳欣樺
• Other Authors: Wu, Tung-Kung
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/34168026957085936862

碩士 === 國立交通大學 === 生物科技學系 === 100 === Hydrogen is a clean renewable energy, putatively to replace fossil energy. In nature, hydrogenses (H2ases) have been closely related with hydrogen evolution. Recent findings allow insight into the active site of the [Fe-Fe] hydrogenase, H-cluster, which catalyzes the reaction of hydrogen production. A series of osmium-sulfur clusters including Os3(CO)12 and various [Os3(S2C3H6)(μ-X)(CO)n] (X = H, COOH; n = 7, 9 etc.) complexes, have been synthesized, purified, and characterized by NMR, IR, and MS spectra. Furthermore, optical characteristics and electrochemical properties of these osmium-sulfur clusters were analyzed by UV-Vis spectrum and cyclic voltammetry. The synthesized osmium-sulfur clusters were subjected to photocatalytic hydrogen generation studies using in the organic phase and the aqueous phase, respectively. In addition, different P-ligands, including (triphenylphosphine (P(Phe)3), tripyrrolephosphine (P(Pyr)3), and tripyrrolidinephosphine (P(Pyrldn)3)) as well as various temperatures (25 ˚C and 40 ˚C) were used to investigate their effects on hydrogen production efficiency. The results showed that [Os6(aspH)(CO)20] (X-1) + P(Pyr)3 exhibits the best hydrogen production efficiency when X-1 was photoirradiated under Xe lamp (500 W) at 40 ˚C in organic phase (TOF = 9.07 h-1). Further studies will focus on the covalent modification of P-ligand onto the osmium-sulfur complexes to improve the efficiency of photocatalytic hydrogen generation and to solve the structures of those osmium-sulfur clusters by X-ray crystallography. The mechanism of hydrogen evolution by various osmium-sulfur clusters will also be elucidated in future.