▎ 摘　　要

Morphology and composition tuning of layered materials is evaluated to influence their electrochemical performance for energy storage and conversion applications. Layered Co1-xNix hydroxides (x=0, 1/2, 1/3, 1/4, 1) of three different morphologies-nanocones, 2 D nanosheets obtained by the rapid exfoliation of nanoconical counterparts, and 2 D superlattice-like nanostructures alternately restacked by the oppositely charged hydroxide and graphene oxide (GO) nanosheets-have been systematically investigated for electrocatalytic oxygen oxidation. High activity is obtained with the 2 D Co2/3Ni1/3 hydroxide nanosheets/GO superlattice (Co2/3Ni1/3NS-GO), achieving a current density of 10 mA cm(-2) at a low overpotential of 259 mV accompanied by a small Tafel slope of 35.7 mV dec(-1), surpassing nanocones and 2 D nanosheets, as well as the congeneric heterostructured Co1-xNix hydroxide nanosheets/GO nanoarchitectures (Co1-xNixNS-GO; x=0, 1/2, 1/4, 1) and the commercial RuO2 electrocatalyst. The outstanding activity of Co2/3Ni1/3NS-GO superlattice uncovers the combined merits of 2 D superlattice-like structure and composition optimization for electrocatalysis, providing a strategy for developing high-performance electrochemical materials by rational morphology and composition design.