Fig. 4From: Photocatalytic and electrocatalytic approaches towards atmospheric nitrogen reduction to ammonia under ambient conditions(Reproduced with permission [32] Copyright 2017, American Chemical Society)a Graphical illustration of the NPC preparation method. b NH3 production rates for NPC-750, NPC-850, and NPC-950. c NH3 production rates at − 0.74 V and − 0.9 V for NPC-750,850 and 950 d Current efficiency of NPC-750. e Recyclability test for NPC-750 for 10 consecutive cycles at − 0.9 VBack to article page