Metal–organic frameworks (MOFs) are gaining considerable interest for various uses ranging from adsorption, photocatalysis, electrocatalysis, chemical sensing, catalysis and gas separation. Fe-based MOFs, especially MIL (53, 68, 88A, 88B, 100 and 101) Fe MOFs which have grown quickly in the last few years, are seen as the most suitable to solve the drawbacks of conventional water purification methods. They have a very porous structure and owing to their superior catalytic activity, contaminant specific adsorption and abundant active sites, Fe-MOF materials are becoming an indispensable device for water processing. Nevertheless, structural decomposition under external photolytic, mechanical, thermal and chemical conditions hinders the further improvement of the activity of Fe-MOFs and their commercialization. In addition, when applied alone in the reaction environment, MIL-Fe particles have a tendency to agglomerate, inhibiting their selectivity and capture efficiency. To overcome these disadvantages, various well-designed MIL-Fe structures have been created via the preparation of composites, heterostructures and doping. Here, we provide a summary of the synthesis, structure and latest advances in the exploitation of MIL-Fe structures (composites and doping) for the elimination and photodecomposition of persistent organic contaminants. Finally, the main challenges, perspectives and future orientations are discussed to provide an insight into the ground-breaking breakthroughs in the field.

A facile chemical procedure was utilized to produce an effective peroxy-monosulfate (PMS) activator, namely ZnCo₂O₄/alginate.

In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi₂WO₆ for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi₂WO₆ orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi₂WO₆, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O₂^•− and holes h⁺ are the principal species responsible for the pollutant photodegradation.