Spinel nanomaterials and their composites as extractors and sensors for heavy metals and other pollutants

Abstract

This extensive review deeply examined the current advancements in spinel metal oxides (SMOs) and their composites. The research studies the use of SMOs and their composites as multifunctional nanomaterials for the extraction and detection of heavy metals and other contaminants. Researchers have utilized SMOs, with their special crystal structure and unique physicochemical properties, as promising materials for sample preparation and detection applications. This study explores their synthesis, properties, sensing, adsorption, and practical applications, emphasizing their role as efficient adsorbents and sensors for heavy metals, pesticides, phenols, and organic dyes. We present a full description of the different SMO synthesis methods, including sol-gel, hydrothermal, and co-precipitation approaches, as well as a discussion of the aspects that influence their shape, stability, and other features. The study discusses the adsorption and sensing mechanisms that explain the higher efficacy of SMOs in the separation and detection of pollutants. Comparison analyses with traditional materials and techniques indicate the advantages of SMOs for sensitivity, selectivity, and reusability, providing a sustainable solution to environmental issues. This review presents schematic representations of synthesis methods and characterizations to help readers fully understand these materials. Furthermore, comparison tables and data reports give perspectives on SMO/SMO-based nanocomposites’ effectiveness across a range of sensing and extraction applications. This study also discusses the limitations and future aspects of SMOs, pointing out the need for more research to improve their performance and scalability. In general, this work serves as a valuable resource for comprehending the current applications of SMOs and their composites in the development of innovative nanomaterials as solutions for various environmental problems.