MOF-Derived Sulfide-Based Electrocatalyst and Scaffold for Boosted Hydrogen Production.

Metal-organic frameworks (MOFs) can act as precursors or templates to a myriad of nanostructured materials that are difficult to prepare. In this study, Co-MOF nanorods (NRs) were prepared at room temperature, followed by calcination and hydrothermal sulfurization strategy to transform the MOF into CoS NRs on carbon cloth (CoS/CC). Intriguingly, the resultant 3D sulfide NRs can serve as scaffolds to electrodeposit layered double hydroxide (LDH) on the surfaces. Through combining the advantages of structure and composition, the as-fabricated CoS@CoNi-LDH/CC exhibits remarkable electrocatalytic activity for hydrogen evolution reaction (HER). An overpotential of 124 mV is needed to reach a current density of 10 mA cm-2 with a Tafel slope of only 89 mV dec-1, which is superior to that of pure CoS/CC (141 mV along with 103 mV dec-1) and other reported cobalt-based catalysts. Notably, after chronopotentiometry test for 50 h, the overpotential of CoS@CoNi-LDH/CC increased by 17 mV only.