Advances in eco-efficient and accelerated sol–gel routes for hybrid nanostructures

Abstract

The sol–gel method is a powerful route for producing ceramics, glasses, and hybrid nanostructures; however, conventional sol–gel processing remains limited by long reaction times, high-temperature treatments, and the use of toxic organic solvents. This review evaluates the hypothesis that combining eco-efficient strategies with accelerated sol–gel routes can significantly improve sustainability and synthesis efficiency while maintaining or enhancing material performance. Reported studies show that eco-efficient formulations can reduce solvent-related hazards and VOC emissions, in some cases approaching reductions of 70–90% depending on the solvent system and precursor chemistry. Processing times have also been shortened substantially, with several reports documenting the reduction of gelation or drying steps from hours to minutes under optimized microwave or ultrasound activation. These quantitative trends are summarized in the revised Table 2 and detailed in the Supplementary Information. These rapid routes also produce hybrid nanomaterials with 20–40% smaller particle sizes, higher homogeneity, and improved optical and catalytic behavior. Emphasis is placed on inorganic–polymer, bioactive glass–biopolymer, and carbon-based hybrid systems, which exhibit enhanced mechanical stability, biocompatibility, and functional versatility. Comparative analysis with conventional sol–gel processes highlight the key advantages, existing gaps, and application relevance in energy, environmental remediation, and biomedical fields. This review provides a concise and up-to-date reference for researchers seeking sustainable, energy-efficient, and high-performance sol–gel strategies for advanced hybrid nanomaterial design.