Constructing ZIF-8@cellulose/graphene hybrids derived 3D-porous cross-linked network based binary hydrated salts thermochemical composite for solar–thermal energy storage

Abstract

Benefiting from the advantages of outstanding storage capacity and retention period, hygroscopic salt thermochemical heat storage (TCHS) materials have evolved into a prospective resolution for channeling the instantaneous accessibility of solar energy into an enduring energy output. Herein, an innovative zeolitic imidazolate framework@graphene oxide-bacterial cellulose (ZIF-8@GO-BC) nanofibrous composite was constructed and its interconnected porous carbonaceous framework (ZGBAC) derivative served as the matrix for TCHS material for the first time. The LiOC3/ZGBAC2 composites are furnished with a remarkable hydratability and storage density up to 1446.8 kJ kg⁻¹ entitled by the collaborative effort between ZGBAC2 features hierarchical 3D cross-linked network scaffold, well-defined porosity, highly exposed surface area, and hygroscopic salt hybrids. Meanwhile, the LiOC3/ZGBAC2–60 could retain 95.7 % of the original heat after 20 repeated reactions while showing great solar–thermal conversion competence owing to the desirable thermal conductivity of ZGBAC2, revealing its promising cycle endurance. And the numerical simulation lends credibility to its excellent heat transfer capability. This study is expected to expand the construction strategy of functionalization-oriented multicomponent carbonaceous frameworks via molecular-level architecture adjustment and may also shed light on novel inspirations for high-increment utilization of nanocellulose in solar energy conversion and storage.