Biomineralization of Sulfate‐Reducing Bacteria In Situ‐Induced Preparation of Nano Fe₂O₃‐Fe(Ni)S/C as High‐Efficiency Oxygen Evolution Electrocatalyst

Abstract

Transition metal‐based catalysts possess high catalytic activity for oxygen evolution reaction (OER). However, the preparation of high‐performance OER electrocatalysts using simple strategies with a low cost still faces a major challenge. Herein, this work presents an innovative, in situ‐induced preparation of the Fe2O3, FeS, and NiS nanoparticles, supported on carbon blacks (CBs) (denoted as Fe2O3‐Fe(Ni)S/C) as a high‐efficiency oxygen evolution electrocatalyst by employing biomineralization. Biomineralization, a simple synthesis strategy, demonstrates a huge advantage in controlling the size of the Fe2O3 and Fe(Ni)S nanoparticles, as well as achieving uniform nanoparticle distribution on carbon blacks. It is found that the electrocatalyst Fe2O3‐Fe(Ni)S/C‐200 shows a good OER electrocatalytic activity with a small loading capacity, and it has a small overpotential and Tafel slope in 1 m KOH solution with values of 264 mV and 42 mV dec−1, respectively, at a current density of 10 mA cm−2. Additionally, it presents good electrochemical stability for over 24 h. The remarkable and robust electrocatalytic performance of Fe2O3‐Fe(Ni)S/C‐200 is attributed to the synergistic effect of Fe2O3, FeS, and doped‐Ni species as well as its distinct 3D spherical structure. This approach indicates the promising applications of biomineralization for the bio‐preparation of functional materials and energy conversion.