Advances in Spinel Ferrite Photocatalysts: From Synthesis, Fundamental Mechanisms, and Solar Energy Conversion Applications

Spinel ferrites (MFe₂O₄) have emerged as versatile photocatalysts due to their tunable optoelectronic properties, chemical stability, and cost-effectiveness. This review discusses the various methods used to synthesize spinel ferrites, comprehensively explores the fundamental mechanisms of photocatalysis in spinel ferrites, followed by the strategies such as morphology control, cation or anion doping, heterojunction fabrication, and surface modification that significantly enhance their optoelectronic performance. These approaches have led to remarkable improvements in visible light absorption, charge separation, and surface reactivity. The subsequent section explores the different solar energy conversion applications using spinel ferrites as photocatalysts. These includes photocatalytic green hydrogen production, photoelectrochemica (PEC)l water splitting, CO₂ photoreduction, pollutant degradation, and photovoltaics. All these applications highlighted the multifunctionality and environmental relevance of spinel ferrites. The last section of the review is dedicated to discuss the challenges related to the research for spinel ferrites with future prospects and recommendations. This compilation provides a roadmap for employing spinel ferrites in solar-driven technologies to address global energy and environmental crises.