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[Display omitted] • Hybrid materials with photothermal conversion performance were prepared for low-energy desorption of NH 3. • Temperature of rGO@MOF-303(Al)-8% could be raised to about 75 °C in 10 min. • About 68% of NH 3 could be effectively desorbed from the adsorbent in 2-hour irradiation. • Excellent desorption performance of NH 3 under sunlight irradiation is attributed to the rapid temperature rise of the adsorbent. The capture, storage and release of NH 3 play a pivotal role in sustainable energy applications. However, to simultaneously achieve high adsorption capacity and low energy desorption remains a challenge. In this work, a novel class of hybrid materials with photothermal conversion performance have been developed by doping redox graphene and metal–organic framework of MOF-303(Al). It is found that the optimized rGO@MOF-303(Al)-8% exhibits high NH 3 uptake (17.0 mmol g−1) at 25.0 °C and 1.0 bar and exceptional photothermal conversion performance. Under the irradiation of simulated sunlight, its temperature can be raised to about 75 °C in 10 min. Even under direct natural sunlight irradiation, a stable equilibrium temperature of 53 °C may be achieved. Based on this excellent photothermal conversion performance, we investigated the desorption behavior of ammonia under visible light irradiation for the first time. We found that due to the breakdown of hydrogen bonds of NH 3 and N-N, N–H sites of rGO@MOF-303(Al)-8% caused by the rapid rise of temperature, approximately 68% of NH 3 could be effectively desorbed in 2-hour irradiation under ambient conditions. In addition, the optimized adsorbent demonstrated remarkable cycling stability. After undergoing 10 cycles, high adsorption capacity and efficient light-induced desorption of NH 3 were still maintained Thus, the present study provides a novel concept for high-capacity adsorption and low-energy desorption of NH 3 and other industrial gases. [ABSTRACT FROM AUTHOR]

[Display omitted] • Al-based MOFs with different number of active sites were developed for efficient adsorption and selective separation of CO 2. • MOF-303(Al) with multiple adsorption sites exhabited a high CO 2 capacity and selectivity of CO 2 to N 2 and CH 4. • MOF-303(Al) can be recycled more than 50 times by a energy-saving desorption process. • Multiple sites interactions of CO 2 with MOF-303(Al) is the key driven force for the adsorption and selective separation. Efficient capture and selective separation of CO 2 is of great significance for alleviating the greenhouse effect. However, it is still a challenge to achieve efficient, reversible and selective capture of CO 2. Here, stable Al-based MOFs with multiple adsorption sites were constructed for capture and selective separation CO 2. It was found that MOF-303(Al) with multiple active sites (μ-OH, N-H, N-N and H-C) demonstrated a high CO 2 capacity of 5.1 mmol/g, and can be recycled for more than 50 times. Moreover, MOF-303(Al) shows excellent selective separation performance of CO 2 from CO 2 /CH 4 and CO 2 /N 2 mixtures, which could be used as a potential material for natural gas purification. Mechanism results revealed that the excellent CO 2 adsorption and selective separation performance is arose from the multiple adsorption sites (μ-OH, N-H, N-N and C-H) of MOF-303(Al), where the contribution of μ-OH and N-H adsorption sites are higher than that of N-N and H-C sites. [ABSTRACT FROM AUTHOR]

Carboxyl functional poly(ionic liquid)s@MOF composites were proposed as a universal adsorption platform to efficiently remove metal ions from water. [Display omitted] • Carboxyl functional ionic liquids guest molecules were incorporated into porous MOF host molecules through in situ polymerization. • Exposing more active sites is beneficial to capture metal ions. • Poly(ionic liquid)s@MOFs exhibit excellent adsorption capacity and recyclability due to the synergistic effect. • The coordination and electrostatic interaction between the carboxyl group and metal ions are the main adsorption mechanism. • This study proposes a new strategy for fabrication functional porous materials to remove metal ions with remarkable efficiency. Development of porous adsorption materials tethered with functional groups was favorable to establish a more efficient, stable and broad-spectrum metal ions removal strategy from water. In this work, carboxyl functional poly(ionic liquid)s@MOF composites were prepared through in situ polymerization of ILs monomers inside MOF pores. Their thermophysical property, structure and morphology were characterized by different techniques. These PILs@MOF composites were proposed as universal and efficient adsorbents to remove selected rare earth metal ions (La3+, Sm3+, Nd3+) and heavy metal ions (Pb2+, Cd2+) from water medium. Effect of pH value and composite dosage on the adsorption efficiency were studied in detail. The optimized adsorption efficiency as high as 99.8 % could be found for the selected metal ions by PIL@MIL-101. In addition, the isotherms, kinetics and thermodynamic parameters of the adsorption process were also determined, and these results imply that the Langmuir model and pseudo-second-order model fitted well with the experimental data. Thermodynamic parameters revealed spontaneous and exothermic nature of the adsorption process. A plausible mechanism for the adsorption process was suggested by the electrostatic interaction and coordination between the carboxyl group and metal ions with the aid of FTIR and XPS measurements. Finally, recycling experiments were performed to demonstrate the recyclability and stability of PIL@MOF composites undergoes at least five adsorption–desorption runs. The current research presented a series of poly(ionic liquid)s@MOF composites as a universal adsorption platform that demonstrated great potential for removing metal ions with remarkable efficiency. [ABSTRACT FROM AUTHOR]