Enhanced electrocatalytic water splitting performance via bimetallic doping in Co-MOF

Abstract

Faced with the pressing issue of severe environmental pollution caused by excessive energy utilization, the search for a new type of fuel that is both environmentally friendly and renewable has become a top priority. In this paper, an efficient bimetallic electrocatalyst material, CoNi-MOF@NF, was synthesized through the hydrothermal synthesis method, which can accelerate hydrogen production via electrolysis. Subsequent electrochemical assessments of CoNi-MOF@NF in an alkaline medium have revealed that, at a current density of − 10 mA/cm², it exhibits an overpotential of 147 mV for hydrogen evolution reaction (HER), and at a current density of 50 mA/cm², it demonstrates an overpotential of 224 mV for the oxygen evolution reaction (OER), outperforming corresponding monometallic electrocatalytic materials. Furthermore, at a current density of 10 mA/cm², it requires a voltage as low as 1.682 V for overall water splitting. In addition, the electrochemical stability of CoNi-MOF@NF was rigorously evaluated through a combination of constant potential (CP) durability testing at 100 mA/cm² for 120 h and accelerated degradation measurements involving 3000 consecutive linear sweep voltammetry (LSV) cycles. These findings unambiguously demonstrate the material’s exceptional operational stability under prolonged electrochemical stress, underscoring its promising potential for practical energy conversion applications.