Shape stable phase change composites based on MXene/biomass-derived aerogel for solar–thermal energy conversion and storage

In this study, a green, non-toxic, and renewable starch was selected to construct a three-dimensional (3D) biomass-derived aerogel to prepare a series of shape stable phase change composites (SSPCCs) by encapsulating organic phase change materials (PCMs), and the best encapsulation effect of SF-50 with ultralow density (0.0635 g/cm−3) and high continuous porosity on polyethylene glycol (PEG) was found to be 91.78 wt% by comparing myristic acid (MA) and paraffin wax (PW). Moreover, the introduction of MXene, a functional two-dimensional filler in the aerogel skeleton, not only endows the SSPCCs with better light absorption ability, but also enhances the encapsulation ability of PEG. The adsorption rate of SF-Mxene-8 on PEG is 93.27 wt% and the enthalpy is 164.92 J/g. In addition, its photothermal conversion rate is 76.9 % and it still has stable solar energy absorption and thermal energy release ability after 200 photothermal conversions. The starch based aerogel in general will bring a new paradigm for PCM as a working medium for solar-thermal energy conversion and storage.