Functional mesoporous poly(ionic liquid)s-derived ultrafine MoP modified N, P-codoped carbon for stable hydrogen production in alkaline media

Abstract

Molybdenum (Mo) based compounds have attracted growing attention in the electrochemical field due to their abundant reserves, high catalytic activity and stability. However, the efficient implementation of MoP for electrocatalytic hydrogen evolution reaction (HER) has been hindered by the limited number of active centers and the weakening electron transferring rate resulting from poor conductivity and easy accumulation during preparation. Herein, we innovate the use of porous poly(ionic liquid)s (MPILs)-loaded phosphomolybdic acid by ion exchange to achieve porous N, P-codoped carbon-encapsulated ultrafine MoP (MoP@NPC). The electronic structure of MoP can be modulated with the carbon matrix, while ultrafine average size of 3 nm nanoparticles afford highly exposed active sites, thus contributing to the boosted electrocatalytic performance of HER. Besides, N, P-codoped carbon coupling with porous structure could facilitate electron transport and shorten the ion transport distance during the electrochemical process. In alkaline media, the optimized MoP@NPC shows small overpotentials of 134 mV with Tafel slopes of 76 mV dec−1 for HER. In addition, excellent electrocatalysis stability has been acquired by MoP@NPC. The in-situ Raman and ex-situ XPS techniques are applied to confirm the superior electrocatalytic HER property of the obtained MoP@NPC. This work provides a new way to prepare a novel Mo-based electrocatalyst by exploiting a special catalyst precursor for hydrogen-energy-related applications.