Hollow layered double hydroxide nanoreactor activated peroxymonosulfate to efficiently degrade dye wastewater

The conventional preparation of layered double hydroxide (LDH) often limits its catalytic effectiveness in advanced oxidation processes due to agglomeration and inadequate exposure of active sites. In this work, we present a simplified synthesis approach that utilizes zeolitic imidazolate frameworks (ZIF)-67 (Co) as a sacrificial template to in situ fabricate hollow polyhedral CoFe-LDH (HP-LDH), aimed at enhancing the degradation of dye contaminants in aqueous systems. The unique porous and polyhedral structure of HP-LDH, derived from the template, facilitates contact efficiency between the substrate and active metal sites, acting as an effective nanoreactor. The comparative degradation experiments of Acid Red 27 (AR27) in peroxymonosulfate (PMS) revealed that the degradation efficiency of HP-LDH was nearly twice that of conventional flake LDH (F-LDH). Under optimal conditions, the HP-LDH/PMS system attained a removal rate of 95% in just 15 min. The degradation of the dye relies on the action of both radical and non-radical species, particularly ¹O₂. Furthermore, the robust adaptability and versatility of HP-LDH/PMS to real water bodies, with a wide range of pH levels and coexisting inorganic anions, demonstrates its potential as a superior catalyst in wastewater treatment, offering a novel pathway for structural innovation of LDH materials in environmental applications.