Electrochemical N₂ reduction offers a promising alternative to the Haber-Bosch process for sustainable NH₃ synthesis at ambient conditions, but it needs efficient catalysts for the N₂ reduction reaction (NRR). Here, we report that FeOOH quantum dots decorated graphene sheet acts as a superior catalyst toward enhanced electrocatalytic N₂ reduction to NH₃ under ambient conditions. In 0.1 M LiClO₄, this hybrid attains a large NH₃ yield rate and a high Faradaic efficiency of 27.3 μg·h^-1·mg^-1_cat. and 14.6% at -0.4 V vs. reversible hydrogen electrode, respectively, rivalling the current efficiency of all Fe-based NRR electrocatalysts in aqueous media. It also shows strong durability during the electrolytic process.