Enhanced photodegradation of reactive dyes in textile effluent with CoFe₂O₄/g-CN heterostructure–mediated peroxymonosulphate activation

Abstract

Graphitic carbon nitride (g-C₃N₄) was employed as a sacrificial substructure and two-dimensional support to develop magnetic cobalt ferrite-carbon nitride (CoFe₂O₄/g-CN) composite via a one-step solid combustion method. The catalyst activated peroxymonosulphate (PMS), through the interconversion of Co^2+/3+|_surf. and Fe^2+/3+|_surf. on its surface for degradation of reactive dyes (RDs). Excellent ferromagnetic nature (44.15 emu g^-1) of the catalyst led to its efficient magnetic separation. With an optimum catalyst and PMS dose of 0.4 g L^-1 and 1.5 g L^-1, 99% RD removal was achieved for textile effluent (pH 9.5–10), under UV irradiation (48 W). In-depth radical scavenging experiments and EPR analysis confirmed the dominance of radical-based degradation process. Plausible degradation and mineralization pathways of RDs were proposed through identification of intermediates by LCMS/MS analysis. In brief, this study elucidates an exclusive strategy towards the use of g-C₃N₄ as fuel for facile synthesis of magnetic CoFe₂O₄/g-CN as a remarkable photocatalyst for activation of PMS towards mineralization of various industrially relevant RDs.