Decoding iron oxide nanoparticles from design and development to real world application in water remediation

[Display omitted] •Recent development of IONPs for wastewater treatment is highlighted.•Overview of synthesis strategies and constraints of IONPs for wastewater treatment.•Comprehensive review on transformations of IONPs and green synthesis routes.•Potential environmental impacts of IONPs for wastewater treatment are outlined.•Challenges and research gaps on large-scale utilization of IONPs are discussed. Over the past decade, incessant research efforts have been devoted to the development of iron oxide nanoparticles (IONPs) for wastewater industry. Past research has witnessed the potential of non-toxic and abundant IONPs to serve as powerful nanosorbents and nanocatalysts, which has become an innovative research point to provide adequate, safe, sustainable, and affordable wastewater treatment for preserving the environment. To improve the efficiency of wastewater treatment process, worldwide researchers have made substantial efforts in tuning the size, morphology, chemical composition, and surface chemistry of IONPs. This review provides an up-to-date overview of the synthesis strategies, limitations and transformation of IONPs for wastewater treatment. Special mentions on the various transformations of IONPs such as functionalization, homogenous-heterogenous catalyst, multifunctional catalyst, and green synthesis routes of IONPs. Finally, the constraints that hinder the real-life applications of IONPs, including the challenges in the development of IONPs with ideal properties, the long-term stability that allows their repeated usage in wastewater treatment, and understanding their potential environmental impacts are outlined. Future research should focus on developing highly efficient and environmental friendly synthesis approaches, optimizing the stability and reusability of IONPs, and conducting thorough assessments of their potential environmental impacts to fully realize the potential of IONPs in the wastewater industry.