▎ 摘　　要

A closed-cycle system for light-harvesting, storage, and heat release is important for utilizing and managing renewable energy. However, combining a high-energy, stable photochromic material with a controllable trigger for solid-state heat release remains a great challenge for developing photothermal fuels (PTFs). This paper presents a uniform PTF film fabricated by the assembly of close-packed bisazobenzene (bisAzo) grafted onto reduced graphene oxide (rGO). The assembled rGO-bisAzo template exhibited a high energy density of 131Whkg(-1) and a long half-life of 37days owing to inter- or intramolecular H-bonding and steric hindrance. The rGO-bisAzo PTF film released and accumulated heat to realize a maximum temperature difference (DT) of 15 degrees C and a DT of over 10 degrees C for 30min when the temperature difference of the environment was greater than100 degrees C. Controlling heat release in the solid-state assembly paves the way to develop highly efficient and high-energy PTFs for a multitude of applications.