Solar hydrogen production from electrochemical ammonia splitting powered by a single perovskite solar cell

Abstract

For carbon-free electrochemical fuel formation, the electrochemical cell must be powered by renewable energy. Obtaining solar-powered H2 fuel from water typically requires multiple photovoltaic cells and/or junctions to drive the water splitting reaction. Because of the lower thermodynamic requirements to oxidize ammonia compared to water, solar cells with smaller open circuit voltages can provide the required potential for ammonia splitting. In this work, a single perovskite solar cell with an open-circuit potential of 1.08 V is coupled to a 2-electrode electrochemical cell employing hybrid electroanodes functionalized with Ru-based molecular catalysts. The device is active for more than 30 min, producing N2 and H2 in a 1:2.9 ratio with 89% faradaic efficiency with no external applied bias. This work illustrates that hydrogen production from ammonia can be driven by conventional semiconductors.