Induced Phosphorization-Derived Well-Dispersed Molybdenum Phosphide Nanoparticles Encapsulated in Hollow N-Doped Carbon Nanospheres for Efficient Hydrogen Evolution

摘要

Molybdenum phosphide (MoP) nanoparticles encapsulated in N,P-codoped hollow carbon nanospheres (MoP@NPC-H) have been synthesized as electrocatalysts for hydrogen evolution reaction (HER) based on an induced phosphorization of an inorganic-organic Mo-P/polyaniline-pyrrole precursor. Notably, the P sources in the polyaniline-p-yrrole precursor are responsible for the formation of well-dispersed MoP nanoparticles and enlarged hollow carbon nanospheres through a P-induced process, which can be described as induced phosphorization for realizing the shift and good dispersion of MoP encapsulated in carbon nanospheres. In addition, the polyaniline-pyrrole precursor could avoid the aggregation of MoP nanoparticles and protect MoP from corrosion during the HER process. N,P-codoped carbon layers provide remarkable conductivity for the higher utilization of active sites. Moreover, compared to solid nanostructures (MoP@NPC-S), the MoP@NPC-H possesses a larger BET surface area and implies superior HER performance, which requires an overpotential of only 141 mV in acidic, 176 mV in alkaline, and 198 mV in neutral solution to achieve a current density of 10 mA cm(-2). The enhancement mechanisms of HER performances have been discussed. The facile approach may provide a new way for preparing highly dispersed MoP encapsulated in carbon materials based on the induced phosphorization.