Surface-oriented heterostructure of iron metal organic framework confined molybdenum disulfides as an efficient bifunctional electrocatalyst for overall water splitting

The rational design of binder free, non-noble, highly active, cost effective and durability of bifunctional electrocatalyst for efficient overall water splitting is crucial for acquiring clean hydrogen energy systems. Herein, a surface-oriented in-situ growth of molybdenum disulfide on the non-precious iron metal organic frameworks is implemented by straightforward two-step solvothermal method. The optimum Fe-MOF@MoS 2 -6h electrocatalyst heterostructures achieves the highly active heterointerfaces of MoS 2 and Fe-MOF, facilitates the mass/charge transport of the catalyst which improves the electrical conductivity. As a consequence, the optimal Fe-MOF@MoS 2 -6h achieves the lowest overpotential of ∼118 mV and ∼187 mV at 10 mA cm −2 for HER and OER, respectively, outperforming benchmark of Pt–C/NF and IrO 2 /NF. Moreover, an overall water splitting electrolyzer constructed using Fe-MOF@MoS 2 -6h||Fe-MOF@MoS 2 -6h electrocatalyst, requires only a cell voltage of 1.517 V to achieve a current density of 10 mA cm −2 which is comparable to Pt–C/NF||IrO 2 /NF (1.588 V) water splitting device. The precisely rational designed bifunctional Fe-MOF@MoS 2 -6h electrode also revealed no degradation in the stability test at 50 mA cm −2 for 100 h in alkaline electrolyte. This work proposes a practical strategy for highly efficient heterointerface electrocatalysts to achieve promising electrochemical water splitting.