BACKGROUND Decontamination of water by means of photocatalysis is seen as a sustainable solution. However, catalysts with low recovery from liquid suspension remain the main predicament that obstructs their industrial applications. To overcome this shortcoming, a methodology is reported here for the functionalization of nanospinel nickel zinc ferrite by cystamine ligand to develop Ni0.5Zn0.5Fe2O4@cystamine magnetic recyclable catalyst for water decontamination applications. RESULTS The diffraction patterns of bare and functionalized nanoferrites indicated that the cubic inverse spinel structure of the particles was not changed after cystamine functionalization. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy analyses confirmed the chemical bonding between cystamine and spinel ferrites. The spherical morphology and elemental composition were studied through high-resolution transmission electron spectroscopy (HRTEM) images and energy-dispersive X-ray (EDX) analysis respectively. Deeper understanding of the catalyst's optical behavior and calculation of the energy band gap were achieved by means of photoluminescence spectroscopy. Magnetic saturation values were calculated from vibrating sample magnetometer (VSM) analysis, and almost negligible change was found. A possible photocatalytic mechanism for the removal of organic dye is proposed. CONCLUSION The present findings imply that the presence of amine groups on the catalyst surface, good dispersibility stability and outstanding catalytic activity make functionalized nanoferrite a suitable candidate for industrial wastewater treatment. Easy synthesis, easy work-up and short reaction times are some of the advantages of the methodology. (c) 2019 Society of Chemical Industry