Experimental investigation on hydrophilic functionalized CaCl2@UIO-66 composites for water adsorption and heat storage

Porous materials with high adsorption capacity can enhance the efficiency of water-based adsorption heat transformation systems. The composites salt in porous matrix (CSPM) are considered to be very promising materials. In this paper, the UIO-66-NH 2 and UIO-66-NO 2 metal-organic framework were used as the porous matrix to synthesize composites with CaCl 2 as the hygroscopic salt. The water adsorption and desorption performance of the composite materials were studied, and the cycle stability was investigated in a continuous adsorption-desorption experiment. As a result, the hydrophilic UIO-66 based composites exhibited higher water adsorption and heat storage capacity. CaCl 2 @UIO-66-NH 2 achieved a water adsorption capacity of 0.84 g/g at 60% relative humidity (RH) and an energy storage density of 1858 J/g. In addition, the hydrophilic UIO-66 based composites exhibited excellent cycle stability, with the quality decreasing by less than 5% after ten adsorption-desorption cycles.