Advances in Aerogel Materials for Energy and Environmental Sustainability

Aerogels have emerged as a unique class of ultralight porous materials that combine exceptional thermal insulation with low density, high porosity, and remarkable structural versatility, enabling broad opportunities across aerospace, energy, electronics, environmental remediation, and wearable technologies. However, their widespread adoption has been constrained by the high cost, limited scalability, and energy-intensive nature of conventional manufacturing processes, particularly supercritical CO₂ drying. This review highlights recent advances in scalable and cost-effective aerogel fabrication, including ambient-pressure drying, templating strategies, top-down manufacturing, chemical vapor deposition, and solution spinning, which collectively enable enhanced performance while significantly reducing production complexity and cost. We further present a unified perspective on the thermal transport physics of porous materials by systematically discussing the mechanisms of solid conduction, gas conduction, convection, and thermal radiation, and comparing aerogels with other porous architectures such as cellular foams. These fundamental insights establish rational design principles for engineering next-generation aerogels with tailored thermal functionalities. Finally, we showcase emerging applications that extend well beyond thermal insulation, including moisture- and water-driven energy harvesting, oil-water separation, high-temperature acoustic insulation, and thermoregulating smart textiles. By bridging scalable manufacturing, fundamental thermal science, and emerging multifunctional applications, this work provides a comprehensive framework for the rational design and commercialization of next-generation aerogels, paving the way toward their widespread adoption in advanced materials and engineering systems.