Synthesis and characterization of titanium-substituted nanocrystalline Co2-Y hexaferrite: magnetically retrievable photocatalyst for treatment of methyl orange contaminated wastewater

Abstract

Rapid industrial growth causes considerable environmental havoc, adversely affecting human and aqueous life. It becomes a significant concern to deal with adequate wastewater treatment strategies by converging on water scarcity. This research work explored the synthesis of titanium-substituted Y-type barium hexaferrite (Co2-Y), having a general formula of Ba2Co2Fe12-xTixO22 (x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5), using a facile nitrate-based sol–gel auto-combustion route and its suitability was investigated as a heterogeneous catalyst within the photo-Fenton-based degradation of methyl orange (MO), one of the significant pollutants generated from textile industries. Developing a thermochemically stable and magnetically separable heterogeneous catalyst for photocatalytic decomposition of nonbiodegradable organic dye from wastewater was also emphasized. The as-prepared nanocrystalline Co2-Y powders were analyzed using XRD, FTIR, DLS, UV–visible spectroscopy, SEM, VSM, and XPS. Furthermore, the photocatalytic degradation performance of pristine and titanium substituted Ba2Co2Fe11.6Ti0.4O22 ferrite, having the lowest bandgap value among all samples, was quantified and compared in terms of apparent rate constant (karc) value and turnover frequency values. The enriched photocatalytic performance was correlated with the existence of multi-valance states of transition metal cations and the availability of oxygen vacancy, confirmed by the surface chemistry using the XPS analysis. The modified (enhanced thermal and chemical stability) hexaferrite catalyst was magnetically separable and reusable without significant losses to its catalytic performance. This promising catalyst may be considered as a replacement for soft ferrite materials to catalyze the degradation of several other nonbiodegradable organic pollutants from wastewater in large-scale industries. Graphical Abstract: [Figure not available: see fulltext.] © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.