Direct electro-phosphorization of nickel and cobalt films in hypophosphite solution for efficient hydrogen evolution.

[Display omitted] • The electrocatalytic activity of Ni and Co films for HER is enhanced by electro-phosphorization. • The electro-phosphorization are realized in hypophosphite solution under electric current action. • Ni film has an overpotential of 57 mV at 10 mA·cm−2 after phosphorization. The electrodeposited nickel and cobalt films are directly phosphorized in alkaline hypophosphite solution under the action of electric current. After the electro-phosphorization process, the morphology of nickel and cobalt films change obviously, and phosphorus element can be detected in the phosphorized films according to the EDS and XPS tests. The electrocatalytic performance of nickel and cobalt films for hydrogen evolution reaction are obviously enhanced by the electro-phosphorization treatment. Especially, the phosphorized nickel film has an overpotential of 57 mV at the current density of 10 mA·cm−2. [ABSTRACT FROM AUTHOR]