Recent Advances in Metal-Organic Framework (MOF)-Based Photocatalysts: Design Strategies and Applications in Heavy Metal Control

Abstract

The heavy metal contamination of water systems has become a major environmental concern worldwide. Photocatalysis using metal-organic frameworks (MOFs) has emerged as a promising approach for heavy metal remediation, owing to the ability of MOFs to fully degrade contaminants through redox reactions that are driven by photogenerated charge carriers. This review provides a comprehensive analysis of recent developments in MOF-based photocatalysts for removing and decontaminating heavy metals from water. The tunable nature of MOFs allows the rational design of composition and features to enhance light harvesting, charge separation, pollutant absorptivity, and photocatalytic activities. Key strategies employed include metal coordination tuning, organic ligand functionalization, heteroatom doping, plasmonic nanoparticle incorporation, defect engineering, and morphology control. The mechanisms involved in the interactions between MOF photocatalysts and heavy metal contaminants are discussed, including light absorption, charge carrier separation, metal ion adsorption, and photocatalytic redox reactions. The review highlights diverse applications of MOF photocatalysts in treating heavy metals such as lead, mercury, chromium, cadmium, silver, arsenic, nickel, etc. in water remediation. Kinetic modeling provides vital insights into the complex interplay between coupled processes such as adsorption and photocatalytic degradation that influence treatment efficiency. Life cycle assessment (LCA) is also crucial for evaluating the sustainability of MOF-based technologies. By elucidating the latest advances, current challenges, and future opportunities, this review provides insights into the potential of MOF-based photocatalysts as a sustainable technology for addressing the critical issue of heavy metal pollution in water systems. Ongoing efforts are needed to address the issues of stability, recyclability, scalable synthesis, and practical reactor engineering.

Hydrogen Production Using Modern Photocatalysts

“…Synthesis or subsequent processing of these materials allows for the incorporation of different types of ligands and metals. The inherent structural arrangement of MOFs enables them to achieve enhanced levels of photocatalytic activity [129][130][131]. The combination of different materials within MOFs could significantly improve hydrogen production performance.…”

Metal–Organic Framework Fe-BTC as Heterogeneous Catalyst for Electro-Fenton Treatment of Tetracycline

“…Metal-organic frameworks (MOFs) are an emerging class of nanomaterials composed of metal ions coordinated to organic linkers. These materials self-assemble into crystalline frameworks with extremely high porosity and surface area that is advantageous for nanomaterial engineering in varied industries such as drug delivery, gas storage and separation, and environmental remediation applications [12][13][14]. Within environmental research, MOFs have been specifically studied for photo-Fenton (PF) degradation of organic water pollutants [15,16] or MOF-derived electro-Fenton degradation of antibiotics [17][18][19][20].…”

An Updated Overview of Magnetic Composites for Water Decontamination

“…When it comes to wastewater, tertiary treatment (Figure 1) is the one referred to as water decontamination in most studies. [11].…”