Paper detail

Designing semiconductor-electrochemical junctions for bioinspired energy transduction

Long ago, life discovered how to efficiently push electrons thermodynamically uphill to lower potential by harnessing energy released by an equal number of electrons moving downhill. Known as electron bifurcation, this form of energy transduction has never been observed in the absence of natural enzymes. To successfully bifurcate electrons, a system must block short-circuit electron transfers that allow all electrons to flow downhill, while maintaining productive reactions. It is difficult to design systems that catalyze these highly-selective electron flows while minimizing free energy dissipation. Using theories of electron transfer and charge transport, I introduce semiconductor-electrolyte junctions that spontaneously bifurcate electrons analogously to natural enzymes (bifurcating junctions). I simulate a simple but illustrative bifurcating junction with typical material properties, and discuss how more complicated designs could achieve higher performance.