摘要：Reduced graphene oxide-azobenzene (RGO-AZO) hybrids were prepared via covalent functionalization for long-term solar thermal storage. Thermal barrier (Δ Ea ) of cis to tran reversion and thermal storage (Δ H ) were improved by molecular hydrogen bonds (H-bonds) through ortho - or para -substitution of AZO. Intramolecular H-bonds thermally stabilized cis - ortho -AZO on RGO with a long-term half-life of 5400 h (Δ Ea = 1.2 eV), which was much longer than that of RGO- para -AZO (116 h). RGO- para -AZO with one intermolecular H-bond showed a high density of thermal storage up to 269.8 kJ kg−1 compared with RGO- ortho -AZO (149.6 kJ kg−1) with multiple intra- and intermolecular H-bonds of AZO according to relaxed stable structures. Thermal storage in experiment was the same order magnitude to theoretical data based on Δ H calculated by density functional theory and packing density. Photoactive RGO-AZO hybrid can be developed for high-performance solar thermal storage by optimizing molecular H-bonds.
