Efficient electroreduction of CO2 to CO by Ag-decorated S-doped g-C3N4/CNT nanocomposites at industrial scale current density

In recent years, the application of graphitic carbon nitride (g-CN) for electrochemical CO reduction reaction (eCORR) has aroused strong interest. However, this material is still facing severe activity issue towards eCORR so far, and studies on its catalytic mechanism have not been sufficiently implemented either. Herein, we report an Ag-decorated sulfur-doped graphitic carbon nitride/carbon nanotube nanocomposites (Ag–S–CN/CNT) for efficient eCORR to carbon monoxide (CO). The resulting Ag–S–CN/CNT catalyst exhibits a notable performance in eCORR, yielding a high current density of −21.3 mA/cm cm at −0.77 V and maximum CO Faradaic efficiency over 90% in H-type cell. Strikingly, when combining with flow cell configuration, the fabricated nanocomposites permit an industrial scale and cost-effective eCORR, showing a current density larger than 200 mA/cm cm and the Faradaic efficiency of CO over 80% in a wide potential window, delivering the best eCORR performance among the CN-derivatives. Moreover, the catalytic mechanism of this nanocomposite has been further explored through density functional theory (DFT) and electrochemical methods carefully. Our work not only sheds light on industrial scale eCORR to CO but also leads to new insights on the application of CN-based composite materials in electrocatalytic processes.