The Schiff base nickel complex functionalised with hydroxyl groups, N,N′-ethylene-bis-(4-hydroxysalicyliminate)nickel(II), [Ni(4-HOsalen)], was anchored onto an air-oxidised activated carbon using cyanuric chloride (CC) as the linking agent. Complex anchoring was made in three consecutive steps: (i) oxidation of activated carbon with a mixture of N2 and air (with 5% O2); (ii) attachment of CC to the air-oxidised carbon surface functionalities, and (iii) reaction between the metal complex functionalised with hydroxyl groups and carbon-bound CC. The carbon-based materials were characterised by elemental analysis, surface techniques (scanning electron microscopy and X-ray photoelectron spectroscopy), X-ray diffraction, nitrogen adsorption isotherms and thermal analysis (temperature-programmed desorption and thermogravimetry). Data from all these techniques provided evidence that the nickel complex was anchored onto the air-oxidised activated carbon via CC.