Free-Standing Dendritic Nanostructured Co/CNT/Carbon Nanofiber Composites for Efficient Water Splitting in Alkaline Media

Exploring highly efficient three-dimensional (3D) nanoarchitectures for H 2 and O 2 evolution reaction (HER and OER) has received tremendous interest. Here, a binder-free free-standing cobalt/bamboo-shaped carbon nanotube/carbon nanofiber (Co/CNT/CNF) film was prepared based on electrospinning, followed by thermal treatment. The synergistic effect between Co cores, CNT shells (5 nm), and CNF skeletons endows the as-prepared Co/CNT/CNF with a 3D porous dendritic nanostructure. Therefore, the unique Co/CNT/CNF film demonstrates prominent HER (overpotential = 129 mV) and OER (overpotential = 162 mV) catalysis behavior at 10 mA cm –2 . Meanwhile, the as-prepared Co/CNT/CNF film displays excellent overall water splitting activity as well as durability (at least 40 h both under 10 and 40 mA cm –2 ). Moreover, the facile electrospinning followed by the thermal treatment approach is economically practical for flexible film production, which has great potential for industrial application in water splitting technology.