Layered Anion‐Mixed Oxycompounds: Synthesis, Properties, and Applications

Layered anion-mixed oxycompounds have emerged as pivotal materials across diverse technological domains encompassing electronics, optics, sensing, catalysis, and energy applications. Capitalizing on the unique properties imparted by the additional anion, these compounds exhibit exceptional characteristics including ultra-large charge carrier mobility, giant second-harmonic generation, visible-light-driven photocatalysis, and outstanding thermoelectricity. This article aims to provide a comprehensive summary of layered anion-mixed oxychalcogenides, oxyhalides, oxynitrides, and oxypnictides. Organized by chemical composition and crystal structures, the classification of these oxycompounds precedes an in-depth exploration of various synthesis methodologies. Subsequently, their properties are elucidated in electronics, optics, magnetics, and ferroelectrics, contextualizing their utility in electronic, optical, and catalytic applications. The review culminates in a critical assessment of extant challenges and opportunities within this realm. Furthermore, insights are proffered into the future trajectory of research, underpinning the significance of advancing novel 2D multi-anion oxygenated compounds and their attendant applications.