Facile synthesis and characterization of advanced cobalt materials for degradative and adsorptive removal of carmoisine in water

The facile synthesis of the advanced cobalt-based materials [1.0Co/Al 2 O 3 (A), 0.5Co/Al 2 O 3 (B), 3.5CoNaY (C) and 0.4CoHY (D)] is reported. The characterization of the materials was carried out by X-ray photoelectronic, energy-dispersive X-ray, atomic absorption and low-temperature nitrogen adsorption methods. These materials were used for a comparative degradative and adsorptive removal of carmoisine azo dye in water. The adsorptive and degradative removals were 62.0–96.1% and 68.1–96.1% for all four materials. The degradation was occurred by hydroxyl radicals and peroxy free radicals. The adsorptive removal followed Langmuir, Temin and Dubinin–Radushkevich models. The adsorption obeyed pseudo-first-order kinetics and liquid film diffusion mechanism. The results indicated that both degradative and adsorptive phenomena had comparative removal capacities. The removal capacities of all four materials were C > A > D > B. The maximum removal was obtained by material C (96.1%) and A (90.0%) in a wide pH range of 3.0–9.0. The reported methods are very effective, efficient and inexpensive for the removal of carmoisine azo dye in water. These methods may be used to remove the reported dye at a large scale in any water resource.