Selective Cobalt over Nickel separation using neat and confined ionic liquids

•Ionic liquids were synthesized by association of tetralkylammonium cations with thiocyanate and dicyanamide coordinating anions.•The dicyanamide-based ionic liquid combined with NaCl medium ensures an efficient separation of Co(II) over Ni(II).•Extraction efficiencies of ground ionogels are comparable to those of neat ionic liquids.•Ionogel ensures a recyclability of metals comparable to those of neat ionic liquids.•Ionogel ensures an efficient separation of Co(II) and Ni(II) in NaCl medium.