Microfluidic-oriented synthesis of enriched iridium nanodots/carbon architecture for robust electrocatalytic nitrogen fixation

Electrocatalytic nitrogen reduction reaction (NRR) is considered as a promising candidate to achieve ammonia synthesis because of clean electric energy, moderate reaction condition, safe operating process and harmless by-products. However, the chemical inertness of nitrogen and poor activated capacity on catalyst surface usually produce low ammonia yield and faradic efficiency. Herein, the microfluidic technology is proposed to efficiently fabricate enriched iridium nanodots/carbon architecture. Owing to in-situ co-precipitation reaction and microfluidic manipulation, the iridium nanodots/carbon nanomaterials possess small average size, uniform dispersion, high conductivity and abundant active sites, producing good proton activation and rapid electrons transmission and moderate adsorption/desorption capacity. As a result, the as-prepared iridium nanodots/carbon nanomaterials realize large ammonia yield of 28.73 μg h−1 cm−2 and faradic efficiency of 9.14% in KOH solution. Moreover, the high ammonia yield of 11.21 μg h−1 cm−2 and faradic efficiency of 24.30% are also achieved in H2SO4 solution. The microfluidic method provides a reference for large-scale fabrication of nano-sized catalyst materials, which may accelerate the progress of electrocatalytic NRR in industrialization field.