Tungsten nitride atomic clusters embedded two-dimensional g-C3N4 as efficient electrocatalysts for oxygen reduction reaction

Abstract Pt-free electrocatalysts for the oxygen reduction reaction (ORR) are valuable with a wide range of applications, but their insufficient activities and stabilities cannot satisfy the commercial requirement. Nitride atomic clusters with the Pt-like electronic structure embedded the conductive and stable g-C3N4 offers an alternative route to promote ORR performance. Herein, we report a facile and in-situ nitriding method to obtain a unique tungsten nitride atomic cluster loaded on the two-dimensional conductive g-C3N4 (WN@g-C3N4) catalyst. In this regard, both the generated cubic-phase WN and its high-dispersed-atomic clusters over the designed 2D g-C3N4 layer are mainly responsible for the excellent ORR performance. Especially for WN@g-C3N4-750, the onset potential and half-wave potential were 0.92 and 0.86 V vs. RHE respectively, identical to the results obtained for the Pt/C catalyst. The results demonstrated that the cubic-phase WN atomic clusters act as active sites, which positively influences the electrocatalytic performance. We believe that the WN@g-C3N4 catalyst with the superior electrocatalytic activity has a strong potential to replace the commercial Pt/C catalyst.