Development and characterization of Co2+ and Al3+ substituted Ni-Cu ferrites for the removal of organic pollutants from wastewater

• Co 2+ and Al 3+ substituted Ni 0.2 Cu 0.8−x Co x Al y Fe 2−y O 4 ferrites were synthesized using the sol–gel auto-combustion method. • XRD , UV–VIS spectroscopy, and dielectric measurements were done. • The photocatalytic degradation efficiency of ferrites was studied by degradation of crystal violet dye. • The prepared ferrites showed 89% degradation activity. Due to modernization and industrial developments, water pollution is increasing daily. It is necessary to treat this water for the sustainability of living beings. Spinal ferrites are promising candidates for the remediation of wastewater. In this study, Co 2+ and Al 3+ substituted nickel copper ferrites Ni 0.2 Cu 0.8−x Co x Al y Fe 2−y O 4 (x = 0, 0.04, 0.08, 0.12, 0.16 y = 0, 0.2, 0.4, 0.6, 0.8) were synthesized via sol–gel method. The impact of Co 2+ and Al 3+ substitution was examined through structural, optical, dielectric , and photocatalytic studies. The cubic spinel structure was confirmed by data obtained through XRD. The average size of ferrites computed by the Williamson-Hall method was 10–18.4 nm. The band gap of ferrites increased from 5.704 eV to 5.863 eV after substituting Co 2+ and Al 3+ cations. Dielectric properties were enhanced after substitution. These ferrites were employed to degrade different dyes. The maximum degradation activity of spinel ferrites in direct sunlight was observed for crystal violet dye which was 89 %. Thus, the prepared spinel ferrites can be considered potential candidates for wastewater treatment.