Flower-like open-structured polycrystalline copper with synergistic multi-crystal plane for efficient electrocatalytic reduction of nitrate to ammonia

Electrocatalytic reduction of nitrate to ammonia is a promising way to regulate the global nitrogen cycle, and is also an important complementary means of ammonia synthesis. However, the convenient preparation of open-structured catalysts with synergistic multi-crystal plane to achieve high efficiency and selectivity is a great challenge. Herein, a flower-like open-structured polycrystalline copper loaded on carbon fiber papers is successfully prepared by linearly varying the deposition potential. This facile approach constructs an open reaction environment with heterogeneous synergistic polycrystalline copper surfaces during the 8-electron reaction, fully enhancing the liquid-phase mass transfer process and the synergistic catalysis process. The optimal sample exhibits the glorious nitrate reduction performance with high ammonia yield of 101.4 μmol h−1 cm−2 and Faradaic efficiency of 93.91% in neutral solution. This work develops a unique self-supporting heterogeneous interface for synergistic catalytic of nitrate, and offers new ideas for simple and rapid implementation of high-performance catalysts for ammonia production from nitrate.