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Mixed matrix membranes (MMMs) containing metal–organic frameworks (MOFs) have been an emerging and promising membrane technology to contribute to different gas separation applications including carbon dioxide (CO2) and oxygen (O2) separation, because of their large surface areas and distinctive gas adsorption features. In this work, the fabrication process of Polydimethylsiloxane (PDMS)-based MMMs was reported, in which 0.5 to 2 wt.% of each type of (Cu, Ni)-based MOF-74 variants were incorporated into a PDMS matrix in order to achieve high CO2/N2, O2/N2, and CO2/O2 separation efficiency. These MMMs and their nanofillers (MOF-74) were extensively characterized using scanning electron microscopy (SEM) along with Energy Dispersive X-Ray (EDX) mapping, X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), a single gas permeation testing system, and an ultimate tensile strength testing (UTS) unit in order to gain insight into their properties in relation to their gas separation performance. The 1 wt.% of both (Cu and Ni)-MOF-74@PDMS were selected as the most optimum MMMs due to their uniform morphology and enhanced tensile strength, which exhibited high CO2 permeabilities of 4432 Barrer (37.9% increase) and 4288 Barrer (33.5% increase), respectively. Furthermore, in the case of 1 wt.% Ni-MOF-74@PDMS, the CO2/N2, O2/N2, and CO2/O2 selectivities were also enhanced to 36.2 (141.6% increase), 3.2 (21.9% increase), and 11.25 (98.1% increase), respectively. While, in the case of 1 wt.% Cu-MOF-74@PDMS the CO2/N2 and O2/N2 selectivities showed an increment up-to 94.7 (531.5% increase) and 6.47 (145% increase), respectively, Whereas, at 0.5 wt.%, Cu-MOF-74@PDMS showed the best CO2/O2 selectivity of 25.26 (344.7% increase). [ABSTRACT FROM AUTHOR]

This, study reports ZIF-8 and its g-C3N4 based composites for successful adsorption of carbon dioxide gas at temperature of 45 °C and 0–15 bar pressure. These samples were characterized via using different techniques like XRD, EDX, SEM, FTIR to study the structural and morphological properties, The SEM results shows rougher and porous rhombic dodecahedron morphology, and the EDX analysis confirms that the catalyst production is free of impurities. The FTIR and XRD analyses show all the peaks and bands correspond to crystalline structure and necessary functional group presence in the prepared adsorbents. The ZIF-8 and its g-C3N4 composites have good adsorption capacity. Among them ZIF-8@3wt% g-C3N4 shows the highest adsorption capacity of 315 mg g−1 at 45 °C and 0–15 bar pressure. The rising adsorption trend of all prepared materials shows that these samples do not reach their saturation point and can still adsorb more CO2 even at a pressure higher than 15 bar. [ABSTRACT FROM AUTHOR]

Aqueous sodium-ion battery is a safe and efficient system for large-scale energy storage due to low cost, abundant sodium supply, non-flammable aqueous neutral electrolyte and quick charge–discharge performance. The use of fluoride-based material as electrode material has a certain advantage due to high potential window and energy density. Exploring perovskite materials has advantage of corner-sharing matrix structure which helps in easy ion and electron diffusion. Herein, we synthesized the perovskite-structured NaNiF3 and its composite with multi-walled carbon nanotubes (MWCNT) by a simple and cost-effective approach by the combination of precipitation and hydrothermal route. The synthesized material is characterized by X-rays diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and Brunauer–Emmett–Teller analysis. Electrochemical performance for aqueous sodium-ion batteries is tested by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy (EIS) in 1 M Na2SO4 electrolyte. XRD confirms the perovskite structure of NaNiF3 and NaNiF3 // MWCNT. SEM shows the orthorhombic cube and cubical structure of NaNiF3 and NaNiF3 // MWCNT. Electrochemical results demonstrate the excellent performance with a specific capacity of 33 mAh g−1 and 57 mAh g−1 at 0.1 A g−1 and shows excellent cyclic stability up to 500 cycles, indicating NaNiF3 // MWCNT as potential candidate among cathode material of aqueous sodium-ion battery. [ABSTRACT FROM AUTHOR]

Processed gas streams from the water gas shift reactor (WGSR) are enriched with CO2 and H2. Purification of H2 from CO2 for different applications is required because of its environmental and economic benefits. Among different separation technologies, membrane technology gets much attention due to its various advantages. In this work, cellulose acetate/polysulfone blended membranes were fabricated via solution casting method for CO2/H2 separation. The separation performance of pure CA membrane was enhanced by addition of PSF. The fabricated membranes were analyzed through various characterization techniques, such as FTIR, SEM, DSC, and XRD. Gas permeation results show that permeability of CO2 increased with increasing concentration of PSF. Notable permeability (P=80.51 Barrer) of CO2 and selectivity of CO2/H2=1.83 of CA/PSF 2 wt% were achieved at 25 °C and 2.5 bar compared to pure CA membrane. To the best of our knowledge, this blend has been studied for the first time for gas separation, prepared through the solution casting method. [ABSTRACT FROM AUTHOR]

In this work, the methanol oxidation reaction is investigated on Ni based metal organic frameworks (MOF) and its composites with biomass derived activated carbon. NiO-MOF and composites with activated carbon were synthesized using hydrothermal method. SEM, EDX, and XRD, FTIR, TGA techniques were used for characterization of composites. The electrochemical activity of catalysts for oxidation of methanol was tested using cyclic voltammetry (CV) in 1 M KOH and 3 M CH3OH on glassy carbon electrode in three electrode setup. The electrochemical performance shows the effect of activated carbon concentration on methanol oxidation. The electro-oxidation catalyzed by NiO-MOF with activated carbon (40 mg) composite exhibits a peak current density of 182.72 mA/cm2 at 0.89 V potential with a scan rate of 50 mV/s making it a potential catalyst for electrocatalysis of methanol. [ABSTRACT FROM AUTHOR]

Present work comprehensively investigated the electrochemical response of Nickel-2 Aminoterephthalic acid Metal–Organic Framework (NiNH2BDC) and its reduced graphitic carbon (rGO) based hybrids for methanol (CH3OH) oxidation reaction (MOR) in an alkaline environment. In a thorough analysis of a solvothermally synthesized Metal–Organic Frameworks (MOFs) and its reduced graphitic carbon-based hybrids, functional groups detection was performed by FTIR, the morphological study by SEM, crystal structure analysis via XRD, and elemental analysis through XPS while electrochemical testing was accomplished by Chronoamperometry (CA), Cyclic Voltametric method (CV), Electrochemically Active Surface Area (EASA), Tafel slope (b), Electron Impedance Spectroscopy (EIS), Mass Activity, and roughness factor. Among all the fabricated composites, NiNH2BDC MOF/5 wt% rGO hybrid by possessing an auspicious current density (j) of 267.7 mA/cm2 at 0.699 V (vs Hg/HgO), a Tafel slope value of 60.8 mV dec−1, EASA value of 15.7 cm2, and by exhibiting resistance of 13.26 Ω in a 3 M CH3OH/1 M NaOH solution displays grander electrocatalytic activity as compared to state-of-the-art platinum-based electrocatalysts. [ABSTRACT FROM AUTHOR]

In this work, we report molybdenum-doped lithium vanadium phosphate Li3MoxV2−x(PO4)3/C synthesized using hydrothermal synthesis to be used as potential cathode material for lithium-ion batteries. The structural characterization of the material was done using X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) which depicted successful incorporation of Mo ion in the Li3V2(PO4)3 structure. Electrochemical properties were studied via constant current charge–discharge cycling. Between the potential range of 2.9–4.3 V, the best sample Li3MoxV2−x(PO4)3/C (x = 0.1) showed the discharge capacities of 152 mAh/g, 130 mAh/g, 110 mAh/g, 90 mAh/g and 70 mAh/g at 0.5C, 1C, 2C, 5C and 10C, respectively. Furthermore, it shows the discharge capacity of 132 mAh/g after 20 cycles at 0.5 C. [ABSTRACT FROM AUTHOR]

Wound care has come through various trials and errors with primitive cultures applying old age techniques and knowledge. Recent research has shown that the moist environment promotes wound healing than the dry. In the present research, hydrogel membranes were fabricated by esterification of polyvinyl alcohol (PVA) with starch and glutaraldehyde as a cross-linker. The essential oils (clove oil, Oregano oil and tea tree oil) have been incorporated in PVA/Starch based hydrogel membranes. The aim was to achieve optimized anti-bacterial activity and mechanical strength. The anti-bacterial testing was performed using the disc diffusion method. The maximum antibacterial activity for fabricated hydrogels was attained by addition of 0.1 mL clove oil in PVA/Starch hydrogel was 39 ± 0.57 mm and 37 ± 0.29 mm for MRSA and E. coli, respectively. The FTIR results presented the occurrence of –OH group in hydrogel membrane. The SEM results showed around dense nature of membranes with having an antibacterial agent in it or not. Mechanical examination of hydrogel membranes presented suitable tensile strength of 19.36 MPa for 0.1 mL Clove oil. Furthermore, water vapour transmission rate (WVTR) and moisture retention capability (MRC) for 0.1 mL clove oil was 36.22 g/m2h and 95.50%, respectively. The experimental conclusion nominated that fabricated hydrogel articulates good antibacterial, mechanical and physical properties that it could be used in wound dressing applications. The best results were obtained for clove oil using 0.1 mL as an antibacterial agent. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate effect of substituents on optoelectronic properties of discotic liquid crystals (DLCs) by using density functional theory (DFT) calculations at B3LYP/Lanl2Z level of theory. Three parent DLCs, namely, (1) benzene-1,3,5-triyl tris(3,5-dialkoxybenzoate), (2) N1, N3, N5-tris(3-alkoxyphenyl)benzene-1,3,5-tricarboxamide, and (3) trialkyl 4, 4′, 4″-(benzenetricarbonyltris (azanediyl)) tribenzoate benzoate and their –N and –S group derivatives of 1, 2, and 3, were investigated to observe the change in optoelectronic response of these systems. The frontier molecular orbital studies and electron affinity values indicate that the studied compounds are stable against the oxygen and moisture present in air. The calculated charge transfer integrals, electron, and hole mobility values revealed that parent DLCs and their derivatives can be employed as an effective n-type material for OLEDs; however, derivatives have enhanced charge transfer values compared with their parents. For better understanding of the thermochemistry and effect of substituents, frequency calculations were carried out. P1-D4 derivative having R = -NH-CO-CH3 terminal group came out to be theoretically the most favored having the lowest ΔG value. Computed UV/visible spectroscopic analysis showed minimum absorbance and maximum transmittance for derivative P2-D1 having –S-NH2 substituent. Molecular electrostatic potential surfaces mapped at potential range, i.e., − 8.531e-3esu to + 8.531e-3esu, describe electrophilic and nucleophilic characteristics. Introduction of electron donor groups enhanced electrical conductivity, excitation energy, and charge transfer integral, thus increasing optoelectronic properties of DLCs. However, these claims require further experimental verification. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate framework-8 (ZIF-8) has a sodalite topology. ZIF-8 is composed of zinc ion coordinated by four imidazolate rings. The pore aperture of ZIF-8 is 3.4 Å, which readily retains large gas molecules like N2. In this work, mixed-matrix membranes (MMMs) have been fabricated by utilizing ZIF-8 and pristine cellulose acetate (CA) for O2/N2 separation. Membranes of pristine CA and MMMs of ZIF-8/CA at various ZIF-8 concentrations were prepared in tetrahydrofuran (THF). Permeation results of the fabricated membranes revealed increasing selectivity for O2/N2 with increasing pressure as well as ZIF-8/CA concentration up to 5% (w/w). The selectivity of O2/N2 increased 4 times for MMMs containing 5% (w/w) of ZIF-8/CA as compared with the pristine CA membrane. A thermodynamic model has also been developed to predict the permeability of gases through polymeric membranes. The results were compared with literature data as well as the pristine CA membrane produced in this work for model validation. [ABSTRACT FROM AUTHOR]

In this study, biomass derived activated carbon (AC) was utilized to enhance the electrochemical properties of copper benzene-1, 3, 5-tricarboxylate metal organic framework (Cu-BTC MOF). Dried leaves (Lantana) were activated with phosphoric acid (H3PO4) for preparation of AC. Cu-MOF was pyrolyzed with different ratios of AC (1:1) under a reduction atmosphere of mixture of argon and hydrogen gases (90:10) in a tube furnace. These freshly produced composite materials were examined by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and thermal gravimetric analysis. The synthesized catalysts were tested for its electro catalytic activity for oxidation reduction reaction (ORR) in three electrode system by cyclic voltammetry, Tafel polarization and electrochemical impedance spectroscopy. The electrochemical parameters calculated by film coated glassy carbon electrode exhibit impact of activated carbon on oxidation reduction reaction catalyzed by Cu-BTC MOF. The composite Cu@AC (1:1) reported the highest current density of 2.11 mA cm−2 at 0.9 V potential with a scan rate of 50 mV s−1 in 0.1 M KOH which is better than commercial grade Pt/C having highest current density of 1.37 mA cm−2 at 0.86 V potential. The electrochemical activity and intensified constancy is due to synergistic influence of MOF and AC-composite. [ABSTRACT FROM AUTHOR]

In present work the development of copper benzenetricarboxylic acid metal organic framework (Cu-BTC MOF) based electrocatalyst and the effect of graphene oxide on catalytic activity of metal organic framework were studied for methanol oxidation reaction. Cu-MOF was prepared by a facile hydrothermal method and graphene oxide flakes were synthesized via improved Hummer's method. Surface morphological studies of catalyst were analyzed through scanning electron microscopy technique, which revealed cubic structure of crystals, while the crystallinity and functional groups present were characterized through X-ray Diffraction and FTIR spectroscopy respectively. Electrochemical studies were conducted by using cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry techniques. Among all series of catalyst, 5 wt% GO/Cu-MOF exhibit highest current density of 120 mA/cm2 at a scan rate value of 50 mV/s at a voltage of 0.9 V. [ABSTRACT FROM AUTHOR]

Abstract: The octane enhancement of light straight run naphtha is one of the significant solid acid catalyzed processes in the modern oil refineries due to limitations of benzene, aromatics, and olefin content in gasoline. This paper aims to examine the role of various catalysts that are being utilized for the isomerization of light naphtha with an ambition to give an insight into the reaction mechanism at the active catalyst sites, and the effect of various contaminants on catalyst activity. In addition, different technologies used for isomerization process are evaluated and compared by different process parameters.Graphical abstract: [ABSTRACT FROM AUTHOR]

The absence of stable and highly active non-precious metal electrocatalysts as a substitute to precious metal i.e., Pt (state-of-the-art) for methanol oxidation reaction in the application of direct methanol fuel cell considerably impedes the commercialization of these energy devices. In this work the electrocatalytic investigation of Fe-In MOF and its g-C3N4-based composites (i.e., 5–8 wt% g-C3N4@ Fe-In MOF) for methanol oxidation is reported. All the catalysts were prepared via solvothermal method. XRD, SEM, EDX, and FTIR were used to characterize the Fe-In MOF and its 5–8wt% g-C3N4 composites. In comparison to other prepared g-C3N4 based Fe-In MOF composites, the 7wt% g-C3N4 @ Fe-In MOF catalyst showed much greater electrochemical activity (i.e., 95.54 mA/cm2) and stability of 72.45% in 1 M NaOH and 3 M CH3OH. Due to graphitic carbon nitride specified high catalytic activity, intercalation, ion exchange, and redox properties. Further, the availability of iron (Fe) and indium (In) may also show a significant role in enhancing the electrocatalytic performance of 7wt% g-C3N4 @ Fe-In MOF over Fe-In MOF. They could be viewed as stable and economical electrocatalysts due to their numerous advantageous characteristics in structure, content, and nitrogen doping level. [ABSTRACT FROM AUTHOR]

In order to promote the electrochemical reduction of CO2 into valuable products and chemical feedstock, the refinement of inexpensive, functioning, highly discerning catalysts is of utmost importance to alleviate inordinate carbon dioxide emissions in the atmosphere. This study presents an innovative electrocatalyst composed of MnO and CuO nanoparticles anchored onto Mn: Cu(1:2)@MOF. These nanocomposites offer multiple active sites for electrochemical carbon dioxide reduction, resulting in a striking current density of almost − 58 mAcm−2 at − 2 V vs. Ag/AgCl (reference electrode) in 0.1 M aqueous KHCO3 electrolyte with faradic efficiency of nearly 52% for CO and 54% for methane at − 1.5 V and − 1.4 V vs. Ag/AgCl, respectively. This performance is in stark contrast to the Mn: Cu(1:1)@MOF and Mn: Cu(2:1)@MOF, which exhibit current densities of − 56 mAcm−2 and − 51 mAcm−2 respectively under similar cathodic voltages. The excellent catalytic accomplishment can be credited to the interaction between nanoparticles and MOFs, which allows enhanced absorption and activation for CO2 molecules due to approachable metallic components and matchless 2-D formation of Mn: Cu(1:2)@MOF. These finding presents a straightforward approach to promote CO2 to valuable products through the analytical formulation of MOF alloy. [ABSTRACT FROM AUTHOR]

To meet the demands for more effective and ecofriendly food packaging strategies, the potential of nisin-loaded rhamnolipid functionalized nanofillers (rhamnosomes) has been explored after embedding in hydroxypropyl-methylcellulose (HPMC) and κ-carrageenan (κ-CR)-based packaging films. It was observed that intrinsically active rhamnosomes based nanofillers greatly improved the mechanical and optical properties of nano-active packaging (NAP) films. Incorporation of rhamnosomes resulted in higher tensile strength (5.16 ± 0.06 MPa), Young’s modulus (2777 ± 0.77 MPa), and elongation (2.58 ± 0.03%) for NAP than active packaging containing free nisin (2.96 ± 0.03 MPa, 1107 ± 0.67 MPa, 1.48 ± 0.06%, respectively). NAP demonstrated a homogenous distribution of nanofillers in the biopolymer matrix as elucidated by scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) confirmed that NAP prepared with nisin-loaded rhamnosomes was thermally stable even above 200 °C. Differential scanning calorimetry (DSC) analyses revealed that addition of nisin in nanofillers resulted in a slight increase in Tg (108.40 °C), indicating thermal stability of NAP. Fourier transform infrared spectroscopy (FTIR) revealed slight shift in all characteristic bands of nano-active packaging, which indicated the embedding of rhamnosomes inside the polymer network without any chemical interaction. Finally, when tested on chicken breast filets and cheese slices under refrigerated storage conditions, NAP demonstrated broad-spectrum antimicrobial activity (up to 4.5 log unit reduction) and inhibited the growth of Listeria monocytogenes, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. These results suggest that HPMC and κ-CR-based NAP containing functionalized nanofillers can serve as an innovative packaging material for the food industry to improve the safety, quality, and shelf-life of dairy and meat products. [ABSTRACT FROM AUTHOR]