Engineering attractive interaction in ZIF-based phase change materials for boosting electro- and photo- driven thermal energy storage

Metal organic frameworks contain abundant empty space for selectively absorbing phase change materials (PCM) molecules and sometimes chemically transformed. However, the strong attractive interaction between metal organic frameworks and PCM severely blocks sufficient crystalline-amorphous state transition of PCM. Herein, we proposed an attractive interaction engineering strategy on hierarchical zeolitic imidazolate frameworks (ZIF) based phase change materials (polyethylene glycol/carbon cloth@ZIF, PEG/CC@ZIF) for boosting crystalline amorphous state transition behavior and electro-/photo-driven thermal performance. Carboxyl-modified CC scaffold regulates attractive interaction between ZIF and PEG, which enhances energy storage capacity of the phase change composite. Moreover, ZIF nanoflakes deposited on the surface of CC reduce the convective heat loss at the solid-gas interface, and CC scaffold facilitates electron transportation and photon penetration, thus significantly enhancing electroand photo-driven thermal energy storage. Furthermore, ZIF-induced chain effect between PEG and CC enhances the mechanical properties of PEG/CC@ZIF. Notably, commercially available transition metal oxide photocatalyst can be uniformly sprayed on the surface of PEG/CC@ZIF through coordination chemical engineering for multi-functional phase change composite.