A novel biochar electrode for efficient electroreduction of nitrate: Selective and regulation of halogen

A novel biochar electrode Bio-Fe3O4/CF used for electroreduction of nitrate was prepared by the hydrothermal synthesis method. The results showed that the growth of spherical Fe3O4 on the surface of smooth biochar can significantly increase the nitrate reduction rate. Besides, the presence of Cl and Br in the solution could promote the conversion of NH4+ to N2, thereby regulating the element nitrogen in the solution. Mechanistic analysis showed that the interconversion of Fe (II) and Fe (III) facilitates the transfer of electrons to nitrate. This study not only provides a biochar electrode material for the efficient removal of nitrate but also simply reveals regulation of halogen in solution, which provides a particular theoretical and data basis for nitrate removal.