Interfacial engineering of MoS2/MoN heterostructures as efficient electrocatalyst for pH-universal hydrogen evolution reaction

The design and development of low-cost and efficient catalysts for hydrogen evolution reaction (HER) from electrochemical water splitting is highly desirable. Constructing the interfacial engineering of heterostructures has been considered to be an effective method to improve the electrocatalytic activity. Here, the MoS2/MoN heterostructures with tuned components have been designed and fabricated by controllable nitridation of the as-prepared flower-like MoS2. The MoS2/MoN heterostructure electrocatalyst displays an efficient HER performance in pH-universal electrolytes, which requires an overpotential of 117 and 132 mV to reach a current density of 10 mA cm−2 in acid (0.5 M H2SO4) and alkaline (1 M KOH) media, respectively (without iR corrections). The good HER performance of MoS2/MoN heterostructures can be ascribed to the hierarchical architecture and the MoS2/MoN interfaces synergistic catalytic effects. X-ray photoelectron spectroscopy (XPS) and work function analysis reveal that MoS2/MoN interfaces synergistically facilitate transport of charge. Furthermore, the density functional theory (DFT) calculations suggest constructing the MoS2/MoN interface can optimize the hydrogen adsorption kinetic energy, thus accelerating the electrochemical HER.