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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. By introducing hydrophilic functional groups, the adsorption capacity, adsorption rate, and thermal storage capacity of CSPMs were improved. [Display omitted] • The hydrophilic functionalized UIO-66 based composites exhibit enhanced water absorption properties. • The hydrophilic functionalized samples have higher energy storage densitywith CaCl 2 @UIO-66-NH 2 reaching 1858J/g. • All samples exhibited good cycle stability and the water adsorption quantity decreased by less than 5% after 10 cycles. [ABSTRACT FROM AUTHOR]

Various articles have been written about MOFs, which are organic-inorganic polymer structures that are unique in three-dimensional porosity, crystalline structure, and their ability to adsorb cadmium ion pollutants from aqueous solutions. These materials possess active metal sites, highly porous structures, high specific surfaces, high chemical functionality, and porous topologies. It is necessary to study adsorption kinetics, isotherms, and mechanisms in order to better understand the adsorption process. Adsorption kinetics can provide information about the adsorption rate and reaction pathway of adsorbents. Adsorption isotherms analyze the possibility of absorbances based on the Gibbs equation and thermodynamic theories. Moreover, in practical applications, knowledge of the adsorption mechanism is essential for predicting adsorption reactions and designing MOFs structures. In this review, the latest suggested adsorption mechanisms, kinetics, and isotherms of MOFs-based materials for removing cadmium ions are presented. A comparison is then conducted between different MOFs and the mechanisms of cadmium ion removal. We also discuss the future role of MOFs in removing environmental contaminants. Lastly, we discuss the gap in research and limitations of MOFs as adsorbents in actual applications, and probable technology development for the development of cost-efficient and sustainable MOFs for metal ion removal. [ABSTRACT FROM AUTHOR]

Abstract: The functionalization of porous metal–organic frameworks (Cu3(BTC)2) was achieved by incorporating Keggin-type polyoxometalates (POMs), and further optimized via alkali metal ion-exchange. In addition to thermal gravimetric analysis, IR, single-crystal X-ray diffraction, and powder X-ray diffraction, the adsorption properties were characterized by N2 and volatile organic compounds (VOCs) adsorption measurements, including short-chain alcohols (C<4), cyclohexane, benzene, and toluene. The adsorption enthalpies estimated by the modified Clausius–Clapeyron equation provided insight into the impact of POMs and alkali metal cations on the adsorption of VOCs. The introduction of POMs not only improved the stability, but also brought the increase of adsorption capacity by strengthening the interaction with gas molecules. Furthermore, the exchanged alkali metal cations acted as active sites to interact with adsorbates and enhanced the adsorption of VOCs. [Copyright &y& Elsevier]