Review on the optimization of iron-based catalysts for Fenton-like reactions through structural and dimensional engineering

Abstract

Iron-based nanoparticles (INPs) are prominent heterogeneous catalysts for H2O2 activation in advanced oxidation processes (AOPs) for wastewater treatment. Their performance is optimized through strategies targeting the Fe3+/Fe2+ cycle, including: (i) composition and defect regulation (e.g., doping/heterojunctions and oxygen-vacancy engineering), (ii) morphological control of iron oxides, zero-valent iron, and Fe-MOFs, (iii) substrate design using one-, two-, and three-dimensional supports, and (iv) spatial confinement in 1D/2D/3D architectures. This review summarizes recent advances in these structural regulation strategies for INPs, focusing on catalytic activity, stability, and reusability. The modulation of local electronic structures, adsorption/transport, and oxidant activation to enhance these properties is discussed. For comparative analysis, we report a single benchmark—the apparent initial molar volumetric rate (r0,molar = kobs × C0,molar)—along with literature removal data. Practical considerations, including Fe-site regeneration, Fe-leaching control, and long-term operation, are also addressed to contextualize the deployment of INP-based catalysts. Future research should focus on achieving durable Fe-valence cycling, improving H2O2 utilization, and developing scalable, low-cost synthesis methods to advance the application of INPs in water pollution control.