Developing molecular solar thermal storage materials based on the reversible isomerization is an important strategy for future efficient solar energy storage and conversion. A new hybrid system composed of azobenzene chromophore (AZO) and multi-walled carbon nanotubes (MCNTs) nano-templates, is designed and prepared via an organosilane as high-energy molecular solar thermal storage material. External high functional density and bundling effect of azobenzenes on the surface of multi-walled carbon nanotubes enable the intermolecular interactions between neighbouring azobenzenes to bring about a conspicuous increase in energy density (77.1 Wh kg(-1)) and half-lifetime (14 h), respectively increased 92.5% and 2 order of magnitudes relative to the pure azobenzene molecule. Simultaneously, AZO-MCNTs nano hybrid maintains ultrastable and reusable stored energy ability for 30 cycles. Our results demonstrate this molecular AZO-MCNTs can practically palliate the daily periodicity of sunlight by storing the solar energy during the day and releasing as heat at night, which can be applied as highly customizable energy storage and conversion technology.