Metal oxide-based hybrid aerogels: materials, synthesis strategies, properties, and emerging applications

Metal oxide-based hybrid aerogels have received growing interest because of their high surface area, porous structure, and tunable electrical, surface, and physicochemical properties, which make them promising for a wide range of applications, including energy storage, sensing, photocatalysis, electromagnetic interference (EMI) shielding, and environmental remediation. Combining metal oxides with conducting polymers, carbon-based materials, and other functional components can improve charge transport, interfacial interactions, and overall functional performance. This review discusses recent developments in the preparation and characterization of metal oxide-based hybrid aerogels and related porous architectures. Different preparation approaches, including sol-gel, hydrothermal synthesis, self-assembly, freeze-drying, and related methods, are briefly discussed in relation to their effects on morphology, porosity, surface properties, and functional properties. The roles of conducting polymers and carbon-based materials in modifying the properties of metal oxide frameworks are also considered. Particular attention is given to their applications in energy storage, electromagnetic interference shielding, photocatalysis, gas sensing, and environmental applications, including the main factors affecting their performance. The review also discusses current limitations, such as reproducibility, structural stability, environmental effects, and the transfer of laboratory-scale materials to practical applications. Finally, some perspectives for the further development of porous hybrid aerogels for advanced functional applications are presented.