Deep Electron Redistributions Induced by Dual Junctions Facilitating Electroreduction of Dilute Nitrate to Ammonia

By constructing the ternary catalyst Co/Co3O4@NC, the electron transfer is relayed through the double heterojunction of Co@Co3O4 and Co3O4@NC, resulting in the deep electronic regulation of Co. As a result, Co/Co3O4@NC exhibits superior performance for diluting electrochemical NO3− reduction reaction (NO3RR) over ever-reported Co-based electrocatalysts. This work provides a promising strategy for deep electronic state regulation of electrocatalysts. AbstractThe electronic states of metal catalysts can be redistributed by the rectifying contact between metal and semiconductor e.g., N-doped carbon (NC), while the interfacial regulation degree is very limited. Herein, a deep electronic state regulation is achieved by constructing a novel double-heterojunctional Co/Co3O4@NC catalyst containing Co/Co3O4 and Co3O4/NC heterojunctions. When used for dilute electrochemical NO3− reduction reaction (NO3RR), the as-prepared Co/Co3O4@NC exhibits an outstanding Faradaic efficiency for NH3 formation (FENH3) of 97.9%, –0.4 V versus RHE and significant NH3 yield of 303.5  mmol h−1 gcat−1 at –0.6 V at extremely low nitrate concentrations (100 ppm NO3−-N). Experimental and theoretical results reveal that the dual junctions of Co/Co3O4 and Co3O4/NC drive a unidirectional electron transfer from Co to NC (Co →Co3O4→NC), resulting in electron-deficient Co atoms. The electron-deficient Co promotes NO3− adsorption, the rate-determining step (RDS) for NO3RR, facilitating the di...

Source: Small - April 16, 2024 Category: Nanotechnology Authors: Lu ‐Hua Zhang, Bo Zhang, Yaohua Hong, Yang You, Yuzhuo Zhou, Jiayu Zhan, David Alonzo Poole III, Fengshou Yu Tags: Research Article Source Type: research