Facile synthesis of zeolitic imidazolate framework-67/vanadium-doped nickel hydroxide as active electrocatalyst for oxygen evolution reaction

Research activities devoted to the development of noble metal-free electrocatalysts have expanded and still require large energy input to drive the oxygen evolution reaction (OER). A key challenge to improve the efficiency of water electrolysis systems is to develop efficient and robust electrocatalysts for water splitting. We propose a simple strategy to construct a nanostructure composed of zeolitic imidazolate framework (ZIF)-67 grafted onto vanadium-doped nickel hydroxide (Ni-V) microflowers (MFs). In this integrated structure, the ZIF-67 polyhedrons were well assembled on the surface of the Ni-V MFs (ie, Z-67/Ni-V), thus enhancing the OER kinetics as a result of the interaction between Ni-V and Co and increasing the electrocatalytic activity. In addition, the Z-67/Ni-V nanostructure is an efficient catalyst that exhibits improved surface area and pore volume. The Z-67/Ni-V nanostructures demonstrated greater OER electrocatalytic activity for alkaline water electrolysis and improved structural stability. Compared to their bare Ni-V-hydroxide counterparts, the Z-67/Ni-V nanostructure reveals an exceptionally low overpotential of 320 mV with a low Tafel slope of 71 mV dec(-1) and remarkable long-standing stability at current density of 10 mA cm(-2).

Automated summary

In this study, a nanostructure composed of zeolitic imidazolate framework and vanadium-doped nickel hydroxide was proposed as a highly efficient and stable electrocatalyst for water splitting. The resulting nanostructure exhibited enhanced electrocatalytic activity, surface area, and pore volume, and demonstrated excellent performance in alkaline water electrolysis.