Computational and experimental elucidation of the boosted stability and antibacterial activity of ZIF-67 upon optimized encapsulation with polyoxometalates

Abstract

Water microbial purification is one of the hottest topics that threats human morbidity and mortality. It is indispensable to purify water using antimicrobial agents combined with several technologies and systems. Herein, we introduce a class of nanosized metal organic framework; Zeolitic imidazolate framework (ZIF-67) cages encapsulated with polyoxometalates synthesized via facile one-step co-precipitation method. We employed two types of polyoxometalates bioactive agents; phosphotungstic acid (PTA) and phosphomolybdic acid (PMA) that act as novel antibacterial purification agents. Several characterization techniques were utilized to investigate the morphological, structural, chemical, and physical properties such as FESEM, EDS, FTIR, XRD, and N2 adsorption/desorption isotherms techniques. The antibacterial assessment was evaluated using colony forming unit (CFU) against both Escherichia coli and Staphylococcus aureus as models of Gram-negative and Gram-positive bacteria, respectively. The PTA@ZIF-67 showed higher microbial inhibition against both Gram-positive and Gram-negative bacteria by 98.8% and 84.6%, respectively. Furthermore, computational modeling using density functional theory was conducted to evaluate the antibacterial efficacy of PTA when compared to PMA. The computational and experimental findings demonstrate that the fabricated POM@ZIF-67 materials exhibited outstanding bactericidal effect against both Gram-negative and Gram-positive bacteria and effectively purify contaminated water.

Optimized Fabrication of Bimetallic ZnCo Metal–Organic Framework at NiCo-Layered Double Hydroxides for Multiple Storage and Capability Synergy All-Solid-State Supercapacitors

“…The FT-IR spectrum of the ZnCo-MOF@NiCo-LDH hybrid was recorded across the wavenumber range of 400− 3800 cm −1 in order to get more insights into the nature of bonding within the assembled hybrid, Figure 2b. The FTIR spectrum of the prepared hybrid displays a sharp band at 428 cm −1 ascribed to the stretching vibration of the M-N, (M = Co, Zn) as a result of the coordination between the metal clusters (Co, Zn) and the N atom of the 2-MIM linker, 36,37 LDH. 17 Moreover, the two sharp bands located at 693 and 754 cm −1 are related to the out-of-plane bending of the imidazole ring, 38 whereas the intercalation of the CO 3 2− and NO 3 − anions within the NiCo-LDH structure can be identified from the absorption bands at 831 and 1384 cm −1 , respectively.…”

“…The FT-IR spectrum of the ZnCo-MOF@NiCo-LDH hybrid was recorded across the wavenumber range of 400–3800 cm –1 in order to get more insights into the nature of bonding within the assembled hybrid, Figure b. The FTIR spectrum of the prepared hybrid displays a sharp band at 428 cm –1 ascribed to the stretching vibration of the M-N, (M = Co, Zn) as a result of the coordination between the metal clusters (Co, Zn) and the N atom of the 2-MIM linker, , whereas the absorption peaks observed at 527 and 673 cm –1 are attributable to the bending vibrations of M–OH/M–O bonds (M = Co, Ni) in the hydrotalcite-like lattice of the bimetallic LDH . Moreover, the two sharp bands located at 693 and 754 cm –1 are related to the out-of-plane bending of the imidazole ring, whereas the intercalation of the CO 3 2– and NO 3 – anions within the NiCo-LDH structure can be identified from the absorption bands at 831 and 1384 cm –1 , respectively. , It is worth noting that the intercalation of anions such as NO 3 – and CO 3 2– should enhance the overall porosity of the surface and augment the contact area between the electrolyte and the electrodes’ surface, respectively. , This intercalation results in boosting the entire electrochemical performance for the material.…”

MOF-Templated Synthesis of Three-Dimensional B-Doped NiCoP Hollow Nanorod Arrays for Highly Efficient and Stable Natural Seawater Splitting

“…From FTIR spectra in Figure 2c, the pristine ZIF-67 nanorod shows strong signals at 424, 1585, and 2923 cm −1 , arising from the stretching vibrations of Co−N, C�N, and C−H, respectively. 37 The bands detected in the 600−1500 cm −1 region are ascribed to the stretching and bending mode of the imidazole ring in ZIF-67. 38 The broad peaks at 3435 cm −1 can be attributed to the hydroxide group.…”

Fe-Single-Atom Catalysts on Nitrogen-Doped Carbon Nanosheets for Electrochemical Conversion of Nitrogen to Ammonia

“…Herein, we demonstrate the design of novel and facile synthesis strategy to anchor iron atoms on N–C network in the form of nanosheet-like morphology, resulting in improved N 2 adsorption on the iron-modified catalyst while suppressing the competing HER. Density functional theory (DFT) calculations have also been employed to elucidate the reaction mechanisms, − electronic properties, and energy barriers. Both experimental and theoretical results are in agreement, confirming the successful design and fabrication of highly active NRR electrochemical catalysts.…”