Nano-Ag modified bio-based loofah foam/polyethylene glycol composite phase change materials with higher photo-thermal conversion efficiency and thermal conductivity

Composite phase change materials have been extensively researched and applied in the field of thermal energy storage management and photo-thermal conversion. In this research, the loofah-based porous carbon (BPC) was modified with nano-Ag particles through chemical reduction method, and then a novel polyethylene glycol (PEG)/modified bio-based loofah porous carbon (BPC-Ag) shape-stable composite phase change material (SSPCM) was prepared. The experimental results indicated that the addition of nano-Ag particles not only considerably improved the thermal conductivity of the PEG/BPC-Ag composite PCMs (from 0.349 W m−1 K−1 to 0.632 W m−1 K−1) compared to the PEG/BPC composite PCMs, but also significantly improved its photo-thermal conversion efficiency (from 76.8 % to 92.3 %). In addition, the PEG/BPC-Ag has excellent thermal stability and reusability, which exhibited favorable phase change performance even after 100 thermal cycles. The results showed that the PEG/BPC-Ag has broad application prospects in the fields of photo-thermal conversion and thermal energy storage management. •This work provides the first example of nano-Ag modified loofah-based porous carbon.•The PEG/BPC-Ag exhibits a high thermal conductivity (0.632 W/m K).•The photo-thermal conversion efficiency of SSPCM can reach 92.3 %.•The relative enthalpy efficiency of the SSPCM can be up to 96.6 %.•The PEG/BPC-Ag has excellent thermal stability and reusability.