SET Proceedings 2978-4387 Caravel Press 10.65582/set.2008.002 2008.002 Waste-to-Energy Conversion for Sustainability: Production of Hydrogen and Elimination of Chemical Wastes in Water with Solar Light ParkHyunwoong LeeT. K. tklee@nano-pac.com HoffmannMichael R. W. M. Keck Laboratories, California Institute of Technology, Pasadena, CA 91125 USA Nanopac, 878-6 Hanyang Plaza 5th Floor, Youngtong-dong, Youngtong-ku, Suwon 443-812 Korea 24082008 7 1 978-1-995850-08-5 16 23 24 August 2008 © 2008 Copyright WSSET 2008

A Bi-doped TiO2 anode, which is prepared from a mixed metal oxide coating deposited on Ti metal, is shown to be efficient for conventional water splitting. In this hybrid photovoltaic – electrochemical system, a photovoltaic (PV) cell is used to convert solar light to electricity which is then used to oxidize a series of phenolic compounds at the semiconductor anode to carbon dioxide with the simultaneous production of molecular hydrogen from water/proton reduction at the stainless steel cathode. Degradation of phenol in the presence of a background NaCl electrolyte produces chlorinated phenols as reaction intermediates which are subsequently oxidized completely to carbon dioxide and low-molecular weight carboxylic acids. The anodic current efficiency for the complete oxidation of phenolic compounds ranges from 3 to 17%, while the cathodic current efficiency and the energy efficiency for hydrogen gas generation range from 68 to 95% and from 30 to 70%, respectively.

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