Sulfur Incorporated CoFe2O4/Multiwalled Carbon Nanotubes toward Enhanced Oxygen Evolution Reaction

Abstract Developing efficient and non-noble metal electrocatalysts for oxygen evolution reaction (OER) at lower overpotential has been considered as a clean and effective strategy for replacing fossil feedstocks. Transitional metal oxides (TMO) electrocatalysts have been actively pursued because of their low-cost and strong stability in alkaline. However, the efficiency for most of developed TMO has been refrained by poor intrinsic electrical conductivity and exposed active sites. Herein, we demonstrate a sulfur incorporation strategy to accomplish greatly optimized OER performance in CoFe 2 O 4 /MWCNT (S-CFO/MWCNT) nanocomposite. Sulfur incorporation into CoFe 2 O 4 not only brings about more active sites in CFO frameworks, but also retains the pristine stable inverse spinel crystal structure which renders the high durability of the S-CFO/MWCNT catalyst. Specifically, the electrocatalysts exhibited greatly optimized OER catalytic activity with overpotential of about 0.36 V achieving current density of about 10 mA cm −2 and Tafel slope of about 43 mV dec −1 , together with stronger stability. Our work demonstrates an effective way to pursue highly efficient OER electrocatalysts.