Modulating the electronic structures derived by neighbouring hetero-diatomic FeCoN6-Gra for prominent electrocatalysis of arsenious acid

Single atom catalysts (SACs) have been widely studied in the field of electrocatalytic reduction, but in the complex multi-step proton-electron reactions, the metal active site is easy to be weakened or even poisoned. Therefore, how to improve the adsorption-desorption capacity and rapid surface reaction to obtain superior electrocatalytic performance remains a great challenge. We indicate the electron synergism of neighbouring Fe and Co diatoms on graphene (FeCoN6-Gra) to promote the electrocatalytic reduction of arsenious acid (As(III)), which is superior to single-atomic catalysts containing only Fe or Co. It is found that the new electron allocation mechanism associated with the injection of Co is beneficial to trigger the two-site adsorption and effectively regulate electron transport between surface sites and As(III). Moreover, the dynamic migration of As(III) driven by Co atom during the reduction process is emphasized, which contributes to break the As-O bond, thus achieving efficient catalysis of the diatomic model. [Display omitted] ●Diatomic catalyst FeCoN6-Gra was prepared for electrocatalysis of As (III).●The injection of Co atoms modulates the electron configuration of the pair.●New electron distribution mechanisms facilitate electron transfer.●Co atom drives the migration of As species and accelerates the breaking of As-O.