Defect-rich fluorographene nanosheets for artificial N2 fixation under ambient conditions

Abstract

NH₃, synthesized by the Haber–Bosch process, is essential for fertilisers in order to feed the world's growing population, however, it causes massive energy consumption and generates large amounts of greenhouse gases. Electrochemical N₂ reduction reaction (NRR) at ambient conditions is highly desirable for energy-efficient and sustainable NH₃ production but this requires an efficient catalyst. In this work, we report a defect-rich fluorographene nanosheet synthesised via fluorination of graphene for NRR electrocatalysis. Such an electrocatalyst shows an NH₃ formation rate of 9.3 μg h⁻¹ mg_cat.⁻¹ and a faradaic efficiency of 4.2% at −0.7 V vs. reversible hydrogen electrode in 0.1 M Na₂SO₄. Density functional theory calculations reveal that the fluorination of graphene induces defects, which not only provide reaction sites for NRR but effectively activate N₂ molecules.