Sustainable Advances in Nanostructure-Doped Polymer Hydrogels for Fog Harvesting: Materials Innovation, Mechanistic Insights and Emerging Applications

Abstract

Globally, water shortages have intensified the search for green and innovative alternatives; among these solutions in arid desert climates is fog harvesting, an evaporative technique for freshwater collection. Nanostructure-doped polymer hydrogels (NSPHs) have recently gained popularity as advanced materials with promising capabilities for effectively enhancing fog harvesting performance due to their desirable structural, thermal, and surface features. Combined with hydrogels, high water absorption and flexibility are achieved. At the same time, nanoparticles enhance surface wettability, thermal conductivity, solar absorption, and directional water transport, all of which improve condensation and collection performance. Recent progress on this topic has been reported using tailored fabrication methods, surface design, and integration to enhance the durability and scalability of NSPHs. Additionally, their flexibility enables the application of these composites in agricultural sustainability, renewable energy, and smart water management. Nevertheless, the individual obstacles remain the cost-efficient manufacturing process, the environmental effects of nanoparticles, and durability under field conditions. Filling these spaces with interdisciplinary research will rapidly commercialize and scale up the implementation of NSPHs, ensuring global water security. This review provides numerous insights into materials innovation, mechanistic understanding, novel applications, and promising research areas, establishing nanoparticle-doped polymer hydrogels as a next-generation sustainable fog-harvesting material.