Heterostructure Ni3P/CoP2/NiCo2O4/CC nanowire material as a trifunctional electrode for high-performance supercapacitors and electrocatalysis

Abstract

The design and preparation of efficient and cost-effective multifunctional active materials for energy storage and conversion are essential component in achieving the current clean energy development. Herein, we have successfully synthesized heterostructure Ni3P/CoP2/NiCo2O4/CC nanowires with vertical array structure on carbon cloth by a simple strategy of solvothermal-annealing and phosphate treatment. The abundant heterogeneous interfaces and synergistic effect between the transition metal oxides/phosphides endow the material with excellent multifunctional properties. As a supercapacitor electrode, the Ni3P/CoP2/NiCo2O4/CC electrode possesses an exceptional specific capacitance of 2349 F g−1 at 1 A g−1. At a power density of 900 W kg−1, the built asymmetric supercapacitor achieves a high energy density of 37.5 Wh kg−1. Furthermore, an initial capacitance retention rate of 85 % was still maintained after 25,000 cycles. When used as electrocatalyst, the required oxygen evolution reaction and hydrogen evolution reaction overpotentials for a current density of 10 mA cm−2 are only 267 mV and 98 mV, respectively. Meanwhile, it presents superior overall water splitting activity (1.64 V@10 mA cm−2) and catalytic stability. This study affords additional perspectives for the reasonable design of non-noble metal based multifunctional materials to meet the diversified energy development.