Self-supported MoP nanocrystals embedded in N,P-codoped carbon nanofibers via a polymer-confinement route for electrocatalytic hydrogen production

Abstract

The development of a controlled synthesis strategy for hierarchical nanostructures with ultrafine metal-based nanocomposites is fundamentally important for high-performance energy technologies. Herein, well-designed nanofiber-like heteroatom-doped carbons with MoP nanocrystals coated on carbon cloth (MoP@NPCF/CC) were prepared through the direct pyrolysis of organophosphonic moiety-modified polyaniline with molybdate. The polymer-confinement effect and in situ phosphorization of this synthetic approach not only impedes the aggregation of metal nanocrystals, but also achieves significantly intimate interaction between the MoP nanocrystals and the conductive carbon nanofibers. Benefiting from the abundant MoP nanocrystals and the doped N and P atoms, and the hierarchical nanofiber structure with binder-free properties, the resultant MoP@NPCF/CC exhibits extraordinary electrocatalytic activity for hydrogen production with the low overpotentials of 115 and 182 mV to afford the current density of 10 mA cm⁻² in H₂SO₄ and KOH electrolytes, together with robust operation durability. In particular, the N,P-codoped carbon nanofibers (NPCF/CC) display high oxygen evolution performance in a KOH medium. Furthermore, employing MoP@NPCF/CC as a cathode and NPCF/CC as an anode, an alkaline electrolyzer configuration achieves the overall current density of 10 mA cm⁻² at 1.64 V, associated with excellent stability. This approach for fabricating such nanostructures will provide new inspiration for exploring advanced electrocatalysts for various energy-related applications.