Ag nanoparticles-reduced graphene oxide hybrid: an efficient electrocatalyst for artificial N2 fixation to NH3 at ambient conditions

For N 2 -to-NH 3 fixation, electrocatalytic N 2 reduction has become one promising alternative to Haber–Bosch process for its superior environmental protection and low-energy consumption. During this electrochemical conversion, adopting a suitable catalytic material is frequently the first consideration that involves in cost and production efficiency. Herein, Ag nanoparticles-reduced graphene oxide hybrid (Ag NPs-rGO) is designed as a novel Ag-based catalyst that exhibits high-efficiency electrocatalytic performance for N 2 -to-NH 3 conversion. Introducing rGO into the catalyst results in a significant improvement of catalytic activity, for the advanced electrical conductivity of rGO and dispersed Ag NPs anchored on this support material. In a 0.1 M Na 2 SO 4 solution, the Ag NPs-rGO delivers Faradaic efficiency of 3.60% and NH 3 yield of 18.86 μg h −1 mg −1 cat. at − 0.7 V versus reversible hydrogen electrode (RHE). By contrast, the Ag NPs attains inferior Faradaic efficiency of 2.25% with NH 3 yield of 9.43 μg h −1 mg −1 cat. (− 0.7 V vs RHE). The Ag NPs-rGO also maintains good stability and sustainability during the electrocatalytic process.