In situ formation of consubstantial NiCo2S4 nanorod arrays toward self-standing electrode for high activity supercapacitors and overall water splitting

Developing high-efficiency, low-cost and environmental friendly electrode materials for both supercapacitors and overall water splitting are significant for renewable energy storage and conversion. Herein, we report a facile consubstantial growth strategy to fabricate subuliform NiCo2S4 nanorod arrays electrode through an in situ growing process, utilizing self-sacrificial Ni foam as substrate and Ni resource. Benefitting from the unique structures, the subuliform NiCo2S4 nanorods can be directly serve as binder-free, trifunctional electrode for overall water splitting with excellent electrocatalytic activity (oxygen evolution reaction with low overpotential of 220 mV at 30 mA cm−2 and hydrogen evolution reaction with low overpotential of 222 mV at 30 mA cm−2) and also as a promising pseudocapacitance electrode with superior electrochemical performance and good stability (high areal capacitance of 8.85 F cm−2 at a current density of 10 mA cm−2 and 94.96% capacitive retention after 10000 cycles). The present work highlights the remarkable advantages of the self-sacrificial strategy for the design of high-performance multifunctional electrode materials.