In-situ calcination of NiO nanowalls@carbon foam with hybrid 2D/3D framework to reinforce 1-octadecanol phase change materials

Abstract

Well-aligned NiO nanowalls on a 3D melamine-derived carbon foam (CF) skeleton were synthesized and further employed in phase change materials (PCMs). The effect of NiO nanowalls and CF on the thermal properties of matrix 1-octadecanol (OD) PCMs was studied in detail. CF with 3D interconnected network and excellent absorption capacities was prepared by simple carbonization from commercial melamine foam (MF). NiO@CF was designed by calcining the precursor of Ni(OH)2 in-situ depositing on CF skeleton. On account of the large specific surface area of NiO nanowalls and the connected networks of CF, NiO@CF/OD composite PCMs possess high thermal storage capacity and excellent heat transfer efficiency. The thermal conductivity and specific heat capacity of NiO@CF/OD composite PCMs are 1.12 W/m·K and 2.80 J/g·K, 4.67 and 2.55 times of pure OD, respectively. The addition of NiO nanowalls and CF had a negligible influence on the phase change temperature of OD. Furthermore, the photothermal energy conversion efficiency of NiO@CF/OD composite PCMs is up to 77.6%. This research opens an avenue to superior multifunctional PCMs possessing high thermal conductivity and great specific heat capacity for low-cost and highly efficient thermal storage technologies.