Self-supported low-crystallinity CoFe layered double hydroxide nanospheres on monolayer Ti3C2 electrode for oxygen evolution reaction

Abstract

The electrocatalytic oxygen evolution reaction is a crucial means to support the conversion and storage of the sustainable renewable energy. Low-crystallinity can offer short-range structural ordering and high active site density. In this work, an efficient self-supported oxygen evolution reaction (OER) electrocatalyst, cobalt iron layered double hydroxide (LDH) grown on Ti3C2 modified nickel foam (NF) heterostructure anode (CoFe-LDH/Ti3C2/NF) was prepared using electrodeposition. The exceptional electrocatalytic OER performance is ensured by in situ decorating monolayer Ti3C2/NF (s-Ti3C2/NF) with low-crystallinity CoFe nanospheres. By harnessing the low crystallinity, well-chosen composition and reasonable heterostructure, the overpotential of CoFe-LDH/Ti3C2/NF decreases to 246 mV at a current density of 10 mA·cm−2 in alkaline media. After 3000 cyclic voltammograms cycles, the ignorable increase in overpotential of 14 mV suggest the excellent long circular stability. Moreover, an accelerated reaction kinetics is implied by the smaller Tafel slope (28.76 mV·dec−1) and higher double-layer specific capacitance (2.33 mF·cm−2), which surpassed the counterparts CoFe-LDH grown on NF (CoFe-LDH/NF) and s-Ti3C2/NF. This work paves a new way to fabricate the low-crystallinity materials for electrocatalysis and energy storage.