Development of metal-organic framework-derived NiMo-MoO3−x porous nanorod for efficient electrocatalytic hydrogen evolution reactions

In this study, we developed a noble metal-free HER electrocatalyst NiMo-MoO3−x porous nanorod (NiMo-MoO3−x −PNR) by optimal thermal reduction of NiMoO4 porous nanorod (NiMoO4 −PNR), where the porous structure of NiMoO4 −PNR was enabled by calcining the designed Ni-Mo-metal-organic framework nanorod (Ni-Mo-MOF−NR). As a result of its ideal porous nanorod structure, composition, and improved bifunctional properties, the electrocatalyst demonstrated superior HER performance (a low overpotential of 24.5 mV @ 10.0 mA cm−2) in 1 м KOH, which was comparable with that of state-of-the-art platinum group metals (PGMs) based electrocatalysts. Furthermore, NiMo-MoO3−x −PNR displayed faster Volmer-Tafel mechanism (a small Tafel slope of 32 mV dec−1) for HER process. The superior HER activity of NiMo-MoO3−x −PNR was supported by density functional theory simulations. Moreover, it exhibited a high cyclic stability (unaffected after 100,000 cycles) and robust durability (102 h). Overall, this study demonstrates a simple, scalable, and versatile synthesis of a noble metal-free highly efficient inexpensive electrocatalyst for HER.