Integration of Fe_(2)O_(3)-based photoanode and atomically dispersed cobalt cathode for efficient photoelectrochemical NH_(3) synthesis

摘要

Realizing nitrogen reduction reaction(NRR) to synthesis NH_(3) under mild conditions has gained extensive attention as a promising alternative way to the energy-and emission-intensive Haber-Bosch process.Among varieties of potential strategies,photoelectrochemical(PEC) NRR exhibits many advantages including utilization of solar energy,water(H_(2)O) as the hydrogen source and ambient operation conditions.Herein,we have designed a solar-driven PEC-NRR system integrating high-efficiency Fe_(2)O_(3)-based photoanode and atomically dispersed cobalt(Co) cathode for ambient NH3 synthesis.Using such solar-driven PEC-NRR system,high-efficiency Fe_(2)O_(3)-based photoanode is responsible for H_(2)O/OH oxidatio n,and meanwhile the generated photoelectrons transfer to the single-atom Co cathode for the N_(2) reduction to NH_(3).As a result,this system can afford an NH_(3) yield rate of 1021.5 μg mg_(co)^(-1) h^(-1) and a faradic efficiency of 11.9% at an applied potential bias of 1.2 V(versus reversible hydrogen electrode) on photoanode in 0.2 mol/L NaOH electrolyte under simulated sunlight irradiation.