Solar to Fuels Conversion By a Monolithic and Standalone Photoelectrochemical Device

Solar to fuels conversion inspired from nature has attracted substantial attention due to a demand for developing sustainable future energy as well as chemical resources. In this presentation, I will introduce our strategy for a highly efficient solar energy to chemical conversion device using CO2 and water as feedstock. For the realization of this architecture we developed a thin film photovoltaic technology for the light absorbing component using a low cost, solution based Cu(InxGa1-x)(SySe1-y)2 (CIGS) fabrication method to provide high enough potential for the conversion reactions. Our solar-fuel device also adapted metal oxide nanoparticle deposited with a low temperature coating method as the water oxidation catalyst and nanostructured metal films as the CO2 reduction to CO or HCOOH generation catalyst. Remarkably, this is the first demonstration of a monolithic and standalone solar-fuel device whose solar-to-fuel conversion efficiency from CO2 and H2O is over 4%, which is comparable to that of photosynthesis in nature. The details of the synthetic method and characterization of each component and the solar-fuel generation system are discussed. Also, some prospects of solar-fuel research for achieving highly efficient solar-fuel production device will be suggested.