Search

Abstract Metal-organic frameworks (MOFs) benefitting from its controllable and diverse structure are a class of promising materials for diverse field. However, its directly employed for oxygen evolution reaction (OER) is still rare. Particularly, two-dimensional (2D) MOF nanosheets materials possess both advantages of 2D layered nanomaterials and MOFs, are considered as promising nanomaterials. Herein, we report a facile and scalable in situ hydrothermal synthesis of a 2D Co-based bimetallic MOFs (Co-Fe/Ni@HPA-MOF nanosheets), which can be stable in alkaline solution and directly adopted as highly efficient electrocatalysts. The Co-Ni@HPA-MOF can reach a current density of 10 mA cm−2 at low overpotential of 320 mV with a small Tafel slope of 58 mV dec−1, which is comparable to that of commercial RuO 2 (58 mV dec−1). The excellent electrocatalytic properties can be attributed to the 2D nanosheet and the coupling effect between Co and Ni, which provided large number of accessible active sites. The results highlight the great potential of utilizing MOF nanosheets for electrocatalysis, and will pave a way to develop more efficient 2D MOFs for diverse catalytic applications. Graphical abstract A facile and scalable in situ hydrothermal synthesis of a two dimensional Co-based bimetallic MOFs (Co-Fe/Ni@HPA-MOF nanosheets) was reported, which can be stable in alkaline solution and directly adopted as highly efficient electrocatalysts. fx1 Highlights • Two dimensional (2D) Co-based bimetallic metal-organic frameworks (MOFs) nanosheets were fabricated. • The Co-Ni@HPA-MOF nanosheet can reach a current density of 10 mA cm−2 at low overpotential of 320 mV. • The excellent electrocatalytic properties can be attributed to the coupling effect between Co and Ni. [ABSTRACT FROM AUTHOR]

In this paper, we reported the fabrication of Co-embedded nitrogen-doped carbon nanotube (Co-NCNT) by using Co-melamine coordination polymer (CP) as precursor. The sample was well characterized via SEM, TEM, XRD, XPS and BET methods. The Co-NCNT shows excellent and stable catalytic performance for OER. The overpotential of Co-NCNT at 10 mA cm -2 is 370 mV (vs RHE). The current density of Co-NCNT could reach 100 mA cm -2 at overpotential of 520 mV, which showed much better performance than RuO 2 , while the largest current density of RuO 2 could reach is only 44 mA cm -2 . The Tafel slope of Co-NCNT is 56 mV dec -1 , which is smaller than that of commercial RuO 2 (58 mV dec -1 ). The results indicate that metal-melamine based CPs or MOFs can be promising precursors for the preparation of efficient metal-embedded nitrogen-doped carbon materials for electrocatalysis. [ABSTRACT FROM AUTHOR]