ABSTRACT
The preparation of metal organic frameworks (MOFs) has come to the forefront in recent years because of their outstanding physical and chemical properties. Many MOFs such as Zn, Co, Ni, Fe, and Ag, etc., have been successfully synthesized. In this work, we followed the solvothermal assisted route to synthesize Ag-MOF (abbreviated as AMOF) nanosheets and then applied them as a photocatalyst to remove different organic pollutants, namely methyl orange (MO), crystal violet (CV), and methylene blue (MB). Chemical composition, optical properties, morphology, and microstructural analysis were analyzed using XPS, UV-visible spectrophotometer, FESEM, TEM, and EDS, respectively. The structural properties of AMOF nanosheets were studied by X-ray diffraction (XRD). Nitrogen adsorption and desorption isotherm analysis were utilized to evaluate the specific surface area and pore size of the AMOF nanosheets. Further, AMOF nanosheets showed notable photocatalytic performance for various dye pollutants degradation. The results confirmed 74.5, 85.5, and 90.7% of MO, CV, and MB dye pollutants removal after 120 min of irradiation with the rate constants (k) of 0.0123, 0.0153, and 0.0158 min-1, respectively. The effect of superoxide radicals (O2-) and photogenerated holes (h+) on the organic dye pollutants removal was investigated using radical scavenger trapping studies. Moreover, the stability study also confirmed the recyclability of the photocatalyst. Therefore, the findings of this research present a realizable method to grow AMOF photocatalyst for successful degradation of various dye pollutants.
ABSTRACT
Supercapacitors (SCs), also known as ultracapacitors, should be one of the most promising contenders for meeting the needs of human viable growth owing to their advantages: for example, excellent capacitance and rate efficiency, extended durability, and cheap materials price. Supercapacitor research on electrode materials is significant because it plays a vital part in the performance of SCs. Polyaniline (PANI) is an exceptional candidate for energy-storage applications owing to its tunable structure, multiple oxidation/reduction reactions, cheap price, environmental stability, and ease of handling. With their exceptional morphology, suitable functional linkers, metal sites, and high specific surface area, metal-organic frameworks (MOFs) are outstanding materials for electrodes fabrication in electrochemical energy storage systems. The combination of PANI and MOF (PANI/MOF composites) as electrode materials demonstrates additional benefits, which are worthy of exploration. The positive impacts of the two various electrode materials can improve the resultant electrochemical performances. Recently, these kinds of conducting polymers with MOFs composites are predicted to become the next-generation electrode materials for the development of efficient and well-organized SCs. The recent achievements in the use of PANI/MOFs-based electrode materials for supercapacitor applications are critically reviewed in this paper. Furthermore, we discuss the existing issues with PANI/MOF composites and their analogues in the field of supercapacitor electrodes in addition to potential future improvements.
ABSTRACT
As of early 2022, only six species bearing an N-O bond have been detected toward cold molecular clouds and regions of star formation. It is not clear yet if the small number of N-O bond species found in the interstellar medium so far stems from physical and technological limitations of astronomical detection techniques, or whether in fact molecules that bear an N-O bond are for some reason rare in these objects of the interstellar medium. Astronomical N-O bearing molecules are important because they are part of astrochemical models which propose that they are precursors of hydroxylamine (NH2OH), a species linked to the formation of prebiotic amino acids in space. The aim of this study is the better understanding of the open question of the interstellar synthesis of N-O bearing species. We have analyzed by infrared spectroscopy an astrophysically relevant polar ice mixture of N2O:H2O processed by 90 MeV 136Xe23+ ions, which can mimic the physicochemical processes triggered by cosmic rays in water-covered interstellar ice grains. The results show the formation of N2O3 and of H2O2, but no HN-O species of any kind were detected. Such findings are discussed in light of recent studies from our group and from the literature.
