Bismuth Ferrite as an Electrocatalyst for the Electrochemical Nitrate Reduction.

Electrochemical nitrate reduction has become an appealing "waste-to-wealth" approach for sustainable NH 3 synthesis owing to its mild operating conditions. However, developing catalysts with high activities and Faradaic efficiencies for this complicated eight-electron reaction is a great challenge. Herein, bismuth ferrite (BiFeO 3 ) flakes, with a distorted perovskite-type structure, are demonstrated to be excellent catalysts for electrochemical NH 3 synthesis via nitrate reduction, with a maximum Faradaic efficiency of 96.85%, NH 3 yield of 90.45 mg h -1 mg cat -1 , at -0.6 V vs. reversible hydrogen electrode. During the nitrate reduction reaction, the crystalline BiFeO 3 rapidly converts into an amorphous phase, which is stable in the long term reaction. These results open a new window for rational design of more active and durable electrocatalysts.