Heterogeneous Fenton catalysts: A review of recent advances

Abstract

Heterogeneous Fenton catalysts are emerging as excellent systems for applications related to water purification. In this review, recent trends in the synthesis and application of heterogeneous Fenton catalysts for the abatement of organic pollutants and disinfection of microorganisms are discussed. It is noted that as the complexity of cell wall increases, the resistance level towards various disinfectants increases and it requires either harsh conditions or longer exposure time for the complete disinfection. In case of viruses, enveloped viruses ( e.g. SARS-CoV-2) are found to be more susceptible to disinfectants than the non-enveloped viruses. The introduction of plasmonic systems with the Fenton catalysts broaden the visible light absorption efficiency of the hybrid material, and incorporation of semiconductor material improves the rate of regeneration of Fe(II) from Fe(III). A special emphasis is given to the use of Fenton catalysts for antibacterial applications. Composite materials of magnetite and ferrites remain a champion in this area because of their easy separation and reuse, owing to their magnetic properties. Iron minerals supported on clay materials, perovskites, carbon materials, zeolites and metal-organic frameworks (MOFs) dramatically increase the catalytic degradation rate of contaminants by providing high surface area, good mechanical stability, and improved electron transfer. Moreover, insights to the zero-valent iron and its capacity to remove a wide range of organic pollutants, heavy metals and bacterial contamination are also discussed. Real world applications and the role of natural organic matter are summarised. Parameter optimisation (e.g. light source, dosage of catalyst, concentration of H 2 O 2 etc. ), sustainable models for the reusability or recyclability of the catalyst and the theoretical understanding and mechanistic aspects of the photo-Fenton process are also explained. Additionally, this review summarises the opportunities and future directions of research in the heterogeneous Fenton catalysis.

Recent Achievements in Dyes Removal Focused on Advanced Oxidation Processes Integrated with Biological Methods

“…Over the past decade, the use of zero-valent iron was demonstrated for treating different varieties of organic and inorganic contaminants, such as dyes [ 190 ]. Thomas et al, in their recent review on heterogeneous Fenton catalysts [ 191 ], reported that zero-valent iron-based technologies have seen huge interest in both mechanistic studies and field applications for the treatment of numerous pollutants due to the environmental compatibility of iron and versatility of the process towards oxidation or reduction reactions. They believed that more applications will be seen in the future, especially if challenges on dispersibility, longevity, and reactivity control are addressed.…”

Iodine Immobilized Metal–Organic Framework for NIR‐Triggered Antibacterial Therapy on Orthopedic Implants

“…Recently, metal–organic frameworks (MOFs) had attracted much attention from researchers as the well‐ordered nanostructure of MOFs offers extra‐large surface area, high loading capacity well‐defined porous structure, and controllable degradation behaviors. [ 20–22 ] By selecting the appropriate organic ligands and reacting conditions, MOF structure formed on materials surface could serve as drug loading and controlled release carriers to facilitate various medical scenarios. [ 23,24 ] In particular, MOFs demonstrate tremendous potential to combat bacterial infections owing to their composition/structure associated features including responsive degradation with bacterial activity, reactive oxygen species (ROS) generation, and capability to load other antibacterial agents.…”

Role of weak magnetic field for enhanced oxidation of orange G by magnetic Fenton

“…However, the large-scale application of homogeneous Fenton system is typically restricted by the low operation pH range (pH = 2.5-3.5) and the generation of undesirable iron sludge (Brillas et al 2009). To minimize negative effects of homogeneous Fenton process, various heterogeneous Fenton catalysts have been developed (Nidheesh 2015, Thomas et al 2020.…”

“…Iron oxides, such as goethite (α-FeOOH), magnetite (Fe 3 O 4 ), and hematite (α-Fe 2 O 3 ), are often treated as heterogeneous Fenton catalysts because of their abundance in earth crust, low cost, negligible toxicity, and environmentally benign (Thomas et al 2020). Compared with hematite and goethite, magnetite (Fe 3 O 4 ) has gain much more attention with its outstanding properties.…”