LAUSR

Abstract Carbon-based electrocatalysts for nitrogen fixation under ambient conditions has attracted tremendous attention but still encounter great challenges of low Faradic efficiency (FE) and a sluggish kinetics. Inspired by intrinsic defects (vacancies, edges and dislocation) on graphene showing activity towards oxygen reduction reaction (ORR) and nitrogen reduction reaction (NRR), here, two commonly exposed surfaces of diamond carbon, i.e., C(111) & C(110), were calculated for electrocatalytic nitrogen reduction reaction (eNRR) by the density functional theory (DFT) method, and calculations show that, compared with C(110), C(111) could be highly promising towards eNRR with a low over-potential (η) of 0.57 V (ΔGmax = 0.73 eV, η = 0.57 V), which are distinctly less than that (ΔGmax = 1.08 eV, η = 0.92 V) of flat benchmark Ru(0001) catalysts. Importantly, these two surfaces are shown to exhibit the suppression of hydrogen evolution reaction (HER). This work is the first reported indication that the low-coordinated carbons (LCCs) on sp3-hybridized diamond-carbon framework are active for eNRR, which gives a brand-new direction of designing/synthesizing sp3-configured diamond-carbon-composited catalysts for eNRR.