Facile synthesis of the Ni-doped carbon sorbents via carbonization of resorcinol–formaldehyde polymers/nickel(II) acetate mixtures in the inert atmosphere.

Effects of Ni content, as well as water volume and temperature treatment on the morphology and texture of the chars.

Ni/C composites are characterized by a core–shell structure with well-crystallized graphitic shells.

Ni content influences the structure of the carbon.

Nickel-doped carbon nanocomposites were used as a magnetically separable adsorbent.