Zinc aluminate (ZnAl₂O₄) spinel nanostructures: fabrication pathways, structure–performance correlations, and application-oriented insights

Abstract

Zinc aluminate (ZnAl₂O₄) nanoparticles have attracted sustained attention due to their outstanding thermal stability, chemical robustness, and versatile optical properties. This review article is intended to present a thorough analysis of the synthetic methods of ZnAl₂O₄ nanomaterials, their synthesis–structure–performance relationship and application-oriented comparison. A systematic and comparative analysis of conventional synthesis techniques—such as sol–gel, co-precipitation, hydrothermal, and microwave-assisted routes—alongside emerging green synthesis and other strategies has been discussed, with explicit emphasis on how processing parameters govern particle morphology, defect chemistry, crystallinity, and functional efficiency. The novelty of this work lies in consolidating dispersed literature data into a unified framework that directly links synthesis conditions to performance metrics relevant to specific technological applications. Key findings demonstrate that rational control of synthesis pathways can substantially enhance photocatalytic activity, catalytic efficiency, and optical response. The review further highlights the practical relevance of ZnAl₂O₄ nanostructures in photocatalysis, heterogeneous catalysis, optoelectronic devices, advanced ceramics, and environmental remediation, offering clear guidelines for designing sustainable and high-performance ZnAl₂O₄ nanomaterials for next-generation technologies.