In recent years, the global warming potential caused by the emission of greenhouse gases has been a
significant concern for climate disasters and rising temperatures in the environment. Conventional
insulators (glass fiber, mineral wool, gypsum board, extruded polystyrene) have more significant
potential in the market share due to their high performance per unit cost. Owing to the low thermal
conductivity, the hydrophobic characteristics of such materials retards heat loss or gain for green
buildings. A facile and cost-effective modified sol-gel synthesis is employed to synthesize flexible silica-
cellulose hybrid aerogels (SCHA) using recycled cellulose fibers (RCF) of three-dimensional cellular
skeletons, Kymene cross-linker and inorganic framework-based methyltrimethoxysilane-derived silica
aerogels as filler through simple freeze-drying. The effect of cellulose fiber concentrations and ambient
temperature conditions on the thermal, acoustic, and oil absorption characteristics was quantified
comprehensively. The experiments were conducted by considering the range of weight fractions from 1
to 4 wt.% from waste tissue paper with a crosslinker and tetraethylorthosilicate (TEOS) as silica
precursors. A similar attempt in the preparation of inorganic graphene oxide (GO) and ferrous oxide was
also made by controlling the mass fraction of phase change materials (PCM) for photothermal
conversion and thermal energy storage in heat exchangers. The synthesized hybrid inorganic porous
frameworks were characterized by XRD, FTIR, SEM, TGA, FESEM, thermal conductivity, DSC, and
BET to identify the physical, chemical and thermal characteristics of the developed sample along with
suitable applicability.