Spinel Aluminate-Based Heterojunctions as Photocatalyst: A Review

The growing demand for sustainable and efficient photocatalysts has driven extensive research into aluminate-based materials due to their high stability, tunable electronic properties and promising photocatalytic performance. Nanocomposites derived from ZnAl₂O₄, MgAl₂O₄, CaAl₂O₄, and SrAl₂O₄ have shown remarkable potential in environmental remediation, particularly in the degradation of organic pollutants under light irradiation. This review explores the synthesis strategies, structural modifications, and performance enhancements of these aluminate-based nanocomposites. Special emphasis is placed on the role of heterojunction engineering, ion doping, and band structure modulation in optimizing charge carrier dynamics and reducing recombination losses. Furthermore, the photocatalytic mechanisms of these materials are critically analyzed through the lens of energy band theory and interfacial charge transfer. The review also identifies current challenges and outlines future research directions, highlighting the potential of aluminate nanocomposites in advanced photocatalytic applications. By providing a systematic overview of their design principles and functional properties, this work aims to serve as a valuable resource for developing next-generation photocatalysts with superior efficiency and stability.