Gyu Leem
State University of New York, USA
Title: Molecular and polymer chromosphere: Catalyst assemblies for solar fuels production
Biography
Biography: Gyu Leem
Abstract
In natural photosynthesis, a multi-chromophore antenna system absorbs light efficiently and transmits excited-state energy rapidly to a reaction center. Related antenna strategies can be available for dye-sensitized photoelectrochemical cells (DSPECs) applications by using polychromophoric polymers. DSPECs convert energy from the sun directly into fuel. Toward fabricating DSPEC devices, we reported the synthesis and properties of novel light harvesting polymers featuring pendant polypyridyl ruthenium complexes. These polymers are ionic polyelectrolytes due to the cationic or anionic charge on the individual chromophore centers. As such, the polyelectrolyte can be utilized to fabricate nanostructured polyelectrolyte layer-by-layer (LbL) films. LbL polyelectrolyte self-assembly allows facile control of the polychromophore-catalyst assemblies prepared directly on the surface of semiconductors. The photophysical and electrochemical properties of the polychromophore-catalyst assembly were characterized at the semiconductor interface. The energy and electron transfer processes were investigated in the polymer assembly. Importantly, prolonged photo electrolysis experiments, with the use of a dual working electrode collector−generator cell, reveal production of O2 and H2 from the illuminated photoanode and photocathode. Polymeric chromophore-catalyst assemblies containing chromophore units and an oxidation catalyst were developed to demonstrate its use in light-driven water oxidation and reduction for a DSPEC application. This is the first report to demonstrate the use of polyelectrolyte LbL to construct chromophore−catalyst assemblies for water splitting reaction.