Multimetallic metal-organic frameworks derived transition metal doped iron selenide arrays for efficient oxygen evolution reaction

A feasible and general strategy based multimetallic metal-organic frameworks template is developed to fabricate hierarchical structured multimetallic selenide. The obtained series of transition metal doped iron selenide exhibit high performance for oxygen evolution reaction (OER). Especially, the Cu-doped FeSe2 electrocatalyst shows the lowest overpotential of 193 mV at a current density of 10 mA cm−2 which outperforms previously reported selenide-based electrocatalysts. The experimental results and theoretical simulations demonstrate that the doping of substitutional Cu in the host lattice of FeSe2 optimizes the electronic structure, being favorable for accelerating the electron transfer and boosting reaction kinetic. Meanwhile, the special structure design enables the electrocatalyst with hierarchical structures, affording rich exposed active sites for efficient OER. Therefore, this work provides a feasible strategy for fabricating hierarchical structured metal selenides for potential electrochemical energy storage and conversion.