The broader impact/commercial potential of this STTR Phase II project will result in significant economic activity through the utilization of waste carbon dioxide. The photo-catalytic reactors funded in the project will lead to novel methods to chemically store energy from the sun. Each year, human activity releases 38 billion tons of carbon dioxide into the atmosphere. Dimensional Energy envisions a future in which we can utilize this carbon dioxide as a feedstock for industrial production of hydrocarbon fuels and chemical intermediaries by harnessing the power of the sun. <br/><br/>This STTR Phase II project proposes to develop HI-Light - a photo-thermo-catalytic reactor platform technology that enables the conversion of CO2 and water to synthesis gas at a rate significantly greater than the state of the art. The unique feature of the technology is that it uses embedded optical waveguides to evenly distribute light within the reactor, increasing the efficacy of the catalyst and ultimately the productivity of the system. In Phase I a fully functional integrated prototype reactor was constructed, demonstrating continuous operation, and showing productivity in terms of the grams of hydrocarbon produced per gram of catalyst per hour more than 10x greater than the state of the art. The approach solves the two major roadblocks in photo-conversion of CO2: (1) the semiconductor catalysts can only use photons with energies greater than their bandgap, which is a small fraction of those present in sunlight and (2) a large fraction of the catalyst material in these reactors is under-utilized due to sub-optimal light and reactant delivery. Our unique reactor uses a patented, multi-scale approach to enhance light and reagent transport directly to the reaction site and makes use of traditionally unused photons to provide heat and enhance reaction efficiency.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.