MoP–MoS2@N-doped carbon heterostructures via sulfur-mediated phosphorization: Synergistic interfaces for efficient hydrogen evolution reaction

Rational heterointerface design is an effective strategy to improve electrocatalytic water splitting. MoP and MoS 2 show “Pt-like” activity but are limited by slow alkaline water dissociation and a high hydrogen-adsorption barrier, respectively. Here, we synthesize MoP–MoS 2 @N-doped carbon (MoP–MoS 2 @NC) heterojunctions through a cysteine-assisted multi-anion coordination and in situ carbonization route. This strategy differs from traditional phosphorization-sulfurization or post-assembly routes. l -cysteine supplies S, N, and C and directs precursor formation, inducing stepwise Mo reduction and programmable MoP/MoS 2 growth during annealing. Precise regulation of the multi-anion coordination environment is realized by adjusting the cysteine dosage, which yields optimal MoP/MoS 2 interfacial coupling. Additionally, cysteine carbonization forms conductive N-doped carbon that further improves performance. The optimized catalyst delivers 115 mV at 10 mA cm −2 and a 66.98 mV dec −1 Tafel slope with excellent stability. This study presents a concise route to multi-anion-derived heterojunction catalysts for efficient hydrogen evolution.