A heterostructure of layered double hydroxide wrapped in few-layer carbon with iridium doping for efficient oxygen evolution

Layered double hydroxides have been studied in various research fields such as electrocatalysis. However, there are still needs to improve their electrochemical performance by designing and fabricating heterostructures with desired crystal architectures as well as tailorable compositions for electrocatalysis. Herein, for the first time a strategy is reported for the synthesis of binary hybrid hydroxide microstructures which are wrapped by few-layer carbon with iridium doping. The synthesized nickel hydroxides enable the epitaxial overgrowth of cobalt hydroxides due to their similar crystal lattice, resulting in the formation of hybrid NiCo layered double hydroxides heterostructures. Moreover, the NiCo layered double hydroxides are coated by few-layer carbon, which is eventually doped by iridium. Our results show that NiCo-Ir hybrid microarchitecture with tunable compositions display excellent electrocatalytic behaviors towards the oxygen evolution reaction, due to their microstructural advantages with thin carbon layers and electronic interaction of iridium/hydroxides. These results validate the potential applications of the NiCo-Ir hybrid microarchitecture in electrocatalysis.