Photoanode Synthesis of Ammonia Using Nice-Layered Double Hydroxide, Bi2o3 with Oxygen Vacancy and Light Reflex

Photoelectrocatalysis or photoelectrochemistry (PEC) strategies to synthesize NH3 by nitrogen reduction reaction (NRR) have attracted considerable attention in recent years, but the PEC-NRR synthesis of NH3 on photoanodes (vs commonly used photocathodes) is still a rather new topic worthy of in-depth study. Herein, the high-performance PEC synthesis of NH3 is achieved on a Bi2O3 with oxygen vacancy plus NiCe-layered double hydroxide modified fluorine-doped tin oxide photoanode biased at 0.4 V vs SCE, and the utilization of light source is improved by an Ag-film-based light reflex. Under optimal conditions, the yield of NH3 is 16.9 mmol h-1 m-2, and it is increased to 28.9 mmol h-1 m-2 after counting the NRR on both the photoanode and the Pt counter electrode, revealing that the photoanode strategy is promising for the green and sustainable synthesis of NH3 under ambient conditions. The NH3-synthesis mechanism is discussed after various characterizations and theoretical calculations.