Highly Efficient Solar Steam Generators Based on Multicore@Shell Nanostructured Aerogels of Carbon and Silica as the Light Absorber−Heat Insulator

Abstract

Herein, highly efficient, low‐cost, and lightweight solar steam generation systems are fabricated using engineered carbon and silica‐based porous nanostructures with 3D networks as light absorber and heat insulator, respectively. In this regard, systems with three different designs are considered to localize the heat efficiently through harvesting more photons and reducing heat losses. The fabricated systems are multilayered structures including polymeric foam and felt as the substrate and water‐carrier medium, respectively. Highly porous nanostructured particles of carbon aerogel (CA) as an absorber, silica aerogel (SiA) as a superinsulator, and multicore@shell aerogel of CA and SiA (CA core−SiA shell) as both absorber and insulator are synthesized. The used architectures are double layered (substrate covered by CA), triple layered (substrate covered by a layer of CA and a layer of SiA), and multicore@shell (substrate covered by CA−SiA multicore@shell aerogel). Using the double‐layered system, an efficiency of 83% corresponding to 1.2 kg m−2 h−1 water evaporation rate is achieved, which is enhanced to 90% in the triple‐layered system, where the SiA superinsulator is added. Remarkably, when the multicore@shell absorber−insulator is used, the efficiency increments of 27% and 16% are achieved compared with the double‐layered and triple‐layered ones with the same amount of absorber, respectively.