Electrochemical synergies of Fe–Ni bimetallic MOF CNTs catalyst for OER in water splitting

Highlights: • FeNi MOF composites with carbon nanotubes were solvothermally synthesized. • Synthesized FeNi MOF-CNTs composites were studied as electrocatalysts for OER in alkaline medium. • FeNiNH₂BDC-5 wt % CNTs composite exhibit superior catalytic activity towards OER. • Stability retained by samples was studied via chronoamperometry experiment. • Synergetic effect between CNTs support and bimetallic MOF catalyst exist. -- Abstract: This work describes electrocatalytic behavior of amiable and economical iron nickel 2-amioterephthalic acid metal organic framework (FeNiNH₂BDC MOF) and its 2–6 wt % carbon nanotubes (CNTs) composites for oxygen evolution reaction (OER) in an alkaline media. Systematic structural and morphological analysis of solvothermally fabricated Iron (Fe) and Nickel (Ni) based MOF and their CNTs composites was carried out by Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray powder diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Brunauer–Emmett–Teller (BET) and energy dispersive X-ray spectroscopy (EDX) techniques. Synergetic effect of bimetallic metal organic framework (MOF) and conductive CNTs support improves the catalytic response of MOF. FeNiNH₂BDC-5 wt % CNTs composite demonstrated current density of 10 mA/cm² at an over potential (η) 0.22 V and onset potential of 1.36 V vs RHE, comparable with RuO₂ state-of-the-art catalytic material for oxygen evolution reaction in a fuel cell. Furthermore, FeNiNH₂BDC-5 wt % CNTs composite tafel slope of 68.50mV/dec and 0.67s⁻¹ turnover frequency (TOF) ascertain it as a promising alternative candidate towards costly Pt, Pd, Ir and Ru based catalysts.