Remarkable enhancement in the electrochemical properties of cosmetic brush-like Co ₃ O ₄ nanowires via in situ surface modification with Ni ²⁺

Abstract Cosmetic brush-like Co ₃ O ₄ nanowires grown on carbon cloth were prepared by regulating the addition of trisodium citrate by hydrothermal synthesis. Then a simple liquid-phase ion exchange was carried out to improve the electrochemical performance of Co ₃ O ₄ by surface modification with Ni ²⁺ . After surface modification, at a current density of 4 A g ^-1 , the specific capacity significantly increased from 276.1 C g ^-1 (720.5 F g ^-1 ) to 655.9 C g ^-1 (1525.4 F g ^-1 ). Meanwhile, the electrocatalytic oxidation performances of methanol and urea were also improved significantly. The enhanced electrochemical properties were attributed to the modification of the surface of Co ₃ O ₄ with Ni ²⁺ .