Photodegradation of organic pollutants is considered to be the most suitable and cheaper technique to counter decontamination issues. Metal nanoparticles are considered the most effective ...heterogeneous photocatalysts for photodegradation of organic pollutants, but neat nanoparticles agglomerate in the reaction medium and display less photocatalytic efficiency. Herein, silica monolith particles (SiO
2
) were synthesized and utilized as a support medium for the synthesis of SnO
2
nanoparticles to retard their agglomeration. Silica-supported tin oxide nanoparticles (SnO
2
/SiO
2
NPs) and neat tin oxide nanoparticles (SnO
2
NPs) were prepared through chemical reduction method and characterized by AFM, SEM, TEM, EDX and mapping, XRD, FTIR and zeta sizer. Morphological and mapping analyses revealed that SiO
2
increases the surface area of SnO
2
NPs and magnificently enhances their photocatalytic activity. The neat SnO
2
NPs are highly agglomerated and hence show less photocatalytic activity. XRD and FTIR analyses confirm the synthesis of SnO
2
NPs. The neat SnO
2
NPs have a PDI of 0.51, which reveal much variation in the particles' size and have a surface charge of −11.2 ± 0.87 mV, which is not enough for the NPs' repulsion in suspended form and hence are agglomerated. The SnO
2
/SiO
2
NPs degraded about 94.58% and 93.73% orange II (O II) dye while SnO
2
NPs degraded 65.93% and 46.11% dye within 30 min irradiation under UV and visible light respectively. The enhanced photocatalytic activity of SnO
2
/SiO
2
NPs is due to the synergistic effect of rapid adsorption followed by drastic photodegradation of dye. The SnO
2
/SiO
2
NPs are much more sustainable than SnO
2
NPs due to easy recycling and washing and the recovered SnO
2
/SiO
2
NPs degraded about 83.38% of dye while SnO
2
degraded 21.91% within 30 min. In addition, the density functional theory (DFT) calculations show that the SnO
2
/SiO
2
NPs have greater adsorption capacity then pristine SiO
2
and SnO
2
surfaces, having shorter binding distances, a larger
E
ads
value (4.29 eV) and a larger reduction in band gap.
Photodegradation of organic pollutants is considered to be the most suitable and cheaper technique to counter decontamination issues.
Flavonoids are a group of naturally occurring polyphenolic secondary metabolites which have been reported to demonstrate a wide range of pharmacological properties, most importantly, antidiabetic and ...anti-inflammatory effects. The relationship between hyperglycaemia and inflammation and vascular complications in diabetes is now well established. Flavonoids possessing antidiabetic properties may alleviate inflammation by reducing hyperglycaemia through different mechanisms of action. It has been suggested that the flavonoids’ biochemical properties are structure-dependent; however, they are yet to be thoroughly grasped. Hence, the main aim of this review is to understand the antidiabetic and anti-inflammatory properties of various structurally diverse flavonoids and to identify key positions responsible for the effects, their correlation, and the effect of different substitutions on both antidiabetic and anti-inflammatory properties. The general requirement of flavonoids for exerting both anti-inflammatory and antidiabetic effects is found to be the presence of a C2–C3 double bond (C-ring) and hydroxyl groups at the C3’, C4’, C5, and C7 positions of both rings A and B of a flavonoid skeleton. Furthermore, it has been demonstrated that substitution at the C3 position of a C-ring decreases the anti-inflammatory action of flavonoids while enhancing their antidiabetic activity. Correlation is discussed at length to support flavonoids possessing essential pharmacophores to demonstrate equipotent effects. The consideration of these structural features may play an important role in synthesizing better flavonoid-based drugs possessing dual antidiabetic and anti-inflammatory effects. A meta-analysis further established the role of flavonoids as antidiabetic and anti-inflammatory agents.
To remove the greenhouse gas N2O from the environment, recently, researchers have taken great interest in single-atom catalysts (SACs). In this study, we investigated various reaction pathways and ...barrier energies for the N2O reduction process onto Si-coordinated phthalocyanine (Si@PthC) employing density functional theory. The outcomes validate that Si decoration in PthC is energetically stable while the corresponding electronic properties show that the Si atom acts as the reactive site for catalytic activity. The N2O molecule exhibits spontaneous dissociation over the catalyst surface from the O-end with −4.01 eV dissociation energy. Meanwhile, N2O dissociation via the N-end involves chemisorption onto the Si@PthC surface with an adsorption energy (Ead) of −1.16 eV, and the dissociation needs an energy barrier of 0.51 eV. The bond distances and negative adsorption energies (−1.11 and −2.40 eV) evince that CO and O2 species chemisorbed onto the Si@PthC surface. However, these energies are smaller than the N2O dissociation energy, which demonstrates that the presence of CO and O2 molecules cannot interrupt the N2O reduction process. Additionally, the CO + O* → CO2 reaction was executed for catalyst recovery, and the reaction proceeds very quickly on the Si@PthC catalyst, with a very small energy barrier (0.37 eV), indicating the excellent catalytic reactivity of the studied catalyst. These results propose that the designed catalyst can be valuable in the progress of novel noble metal-free catalysts for the elimination of harmful N2O from the environment.
In this article we report novel composite materials of bucky ball (C
60
fullerene) and III-nitrides (BN, AlN, GaN, InN). The experimental feasibility of the novel composite materials is confirmed ...through negative binding energies and molecular dynamics simulations performed at 500 K. The structural properties of the novel composites are explored through density functional theory. An unusual phenomenon of surface bowing is observed in the 2D structure of the III-nitride monolayers due to the C
60
sticking. This surface bowing systematically increases as one proceeds from BN → AlN → GaN → InN. The electron density difference and Hirshfeld charge density analysis show smaller charge transfer during the complexation, which is probably due to weak van der Waal's forces. The presence of van der Waal's forces is also confirmed by the Atom in Molecule analysis, Reduced Density Gradient Technique and Non-covalent Interaction analysis. This work provides a foundation for further theoretical and experimental studies of the novel phenomenon of systematic bowing in the 2D structure of III-nitride monolayers.
This work reports systematic surface bowing in the 2D structure of III-nitrides due to the C
60
adsorption as we proceed from BN → AlN → GaN → InN.
Porous crystalline materials such as covalent organic frameworks (COFs) have gained tremendous popularity in multidisciplinary areas of science and technology. In this study, for the first time, we ...report a covalent triazine-based framework (CTF-1) as an efficient adsorbent for the removal of Cd
2+
from aqueous solutions. CTF-1 offered excellent stability under extreme conditions for the effective removal of cadmium cations (Cd
2+
) from aqueous solutions. CTF-1 was first synthesized through an ionothermal method and then characterized by XRD, SEM, TEM and BET surface area measurements to confirm its highly crystalline and microporous nature. Batch adsorption experiments were systematically conducted under a wide range of pH, metal ions concentration, adsorbent dosage and contact time to investigate kinetics, thermodynamics and adsorption properties of CTF-1 towards Cd
2+
ions removal. The pseudo-second-order model showed good fitting to experimental data, whereas Langmuir and D-R isotherms confirmed the chemical nature of the adsorption. Similarly, thermodynamic parameters indicated the adsorption to be spontaneous and endothermic. Furthermore, our simulation results showed that CTF-1 possess uniform distribution of negative charge along the framework, making it an ideal candidate for the adsorption of cations together with the high stability in both acidic and basic pH. The strategies adopted in this study will open a new avenue to design novel nanoporous functional materials for next generation adsorbents.
Porous crystalline materials such as covalent organic frameworks (COFs) have gained tremendous popularity in multidisciplinary areas of science and technology.
The geometries, electronic structures, and catalytic properties of BN-codoped fullerenes C59−nBNn (n = 1–3) are studied using first-principles computations. The results showed that BN-codoping can ...significantly modify the properties of C60 fullerene by breaking local charge neutrality and creating active sites. The codoping of B and N enhances the formation energy of fullerenes, indicating that the synergistic effects of these atoms helps to stabilize the C59−nBNn structures. The stepwise addition of N atoms around the B atom improves catalytic activities of C59−nBNn in N2O reduction. The reduction of N2O over C58BN and C57BN2 begins with its chemisorption on the B–C bond of the fullerene, followed by the concerted interaction of CO with N2O and the release of N2. The resulting OCO intermediate is subsequently transformed into a CO2 molecule, which is weakly adsorbed on the B atom of the fullerene. On the contrary, nitrogen-rich C56BN3 fullerene is found to decompose N2O into N2 and O* species without the requirement for activation energy. The CO molecule then removes the O* species with a low activation barrier. The activation barrier of the N2O reduction on C56BN3 fullerene is just 0.28 eV, which is lower than that of noble metals.
Twenty-four analogues of benzimidazole-based thiazoles (1–24) were synthesized and assessed for their in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory potential. All ...analogues were found to exhibit good inhibitory potential against cholinesterase enzymes, having IC50 values in the ranges of 0.10 ± 0.05 to 11.10 ± 0.30 µM (for AChE) and 0.20 ± 0.050 µM to 14.20 ± 0.10 µM (for BuChE) as compared to the standard drug Donepezil (IC50 = 2.16 ± 0.12 and 4.5 ± 0.11 µM, respectively). Among the series, analogues 16 and 21 were found to be the most potent inhibitors of AChE and BuChE enzymes. The number (s), types, electron-donating or -withdrawing effects and position of the substituent(s) on the both phenyl rings B & C were the primary determinants of the structure-activity relationship (SAR). In order to understand how the most active derivatives interact with the amino acids in the active site of the enzyme, molecular docking studies were conducted. The results obtained supported the experimental data. Additionally, the structures of all newly synthesized compounds were elucidated by using several spectroscopic methods like 13C-NMR, 1H-NMR and HR EIMS.
This study reports the isolation of three new C20 diterpenoid alkaloids, Chitralinine A–C (1–3) from the aerial parts of Delphinium chitralense. Their structures were established on the basis of ...latest spectral techniques and single crystal X-rays crystallographic studies of chitralinine A described basic skeleton of these compounds. All the isolated Compounds (1–3) showed strong, competitive type inhibition against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in comparison to standard allanzanthane and galanthamine however, chitralinine-C remained the most potent with IC50 value of 11.64 ± 0.08 μM against AChE, and 24.31 ± 0.33 μM against BChE, respectively. The molecular docking reflected a binding free energy of −16.400 K Cal-mol−1 for chitralinine-C, having strong interactions with active site residues, TYR334, ASP72, SER122, and SER200. The overall findings suggest that these new diterpenoid alkaloids could serve as lead drugs against dementia-related diseases including Alzheimer’s disease.
•Optimisation of slow pyrolysis parameters for alkali, prot and dealkaline lignin.•Maximum biooil yield (34.1wt.%) obtained alkali lignin at 450°C.•Ca. 35wt.% of guaiacols obtained form prot lignin ...at 300°C.•Maximum yield (92%) of phenolic compounds from dealkaline lignin at 350°C.•Relative contents of each phenolic compound changes significantly with pyrolysis temperature.
Effect of different lignins were studied during slow pyrolysis. Maximum bio-oil yield of 31.2, 34.1, and 29.5wt.% was obtained at 350, 450 and 350°C for prot lignin, alkali lignin and dealkaline lignin respectively. Maximum yield of phenolic compounds 78%, 80% and 92% from prot lignin, alkali and dealkaline lignin at 350, 450 and 350°C. The differences in the pyrolysis products indicated the source of lignins such as soft and hard wood lignins. The biochar characterisation revealed that the various ether linkages were broken during pyrolysis and lignin was converted into monomeric substituted phenols. Bio-oil showed that the relative contents of each phenolic compound changes significantly with pyrolysis temperature and also the relative contents of each compound changes with different samples.
l-Cyteine is a form of amino acid found in human body. Retaining the exact quantity of l-Cyteine is important for better functioning of the body. A novel hybrid TiO2 nanostructure (H-TNTs) was ...prepared on both sides of Ti sheet using the first-step anodization in used (residual) ethylene glycol (EG) based electrolyte. The H-TNTs was explored as an enzyme-free electrochemical biosensor for the detection of l-Cysteine (L-Cyst) and hydrogen peroxide (H2O2). Structural analysis revealed that annealed H-TNTs was anatase with uniform tube morphology and narrow pore size distribution of the top thin nanoporous layer. Electrochemical measurements demonstrated excellent electrocatalytic activities of H-TNTs with sensitivity and rapid response of L-Cyst (0.9914 μA mM−1 cm−2, <2 s) and H2O2 (85.3 μA mM−1 cm−2, < 5 s) respectively. The DFT analysis described that TNT has greater affinity towards L-Cyst and H2O2 with stronger binding distances after the adsorption. The higher negative Eads values suggesting the stable and chemisorptions nature of the H-TNTs. The density of states (DOS) results show that Egap of TNT was significantly reduced after both molecules adsorption. The fabricated electrochemical biosensor exhibited decent stability, excellent reproducibility, and good resistance to interfering molecules showing great potential, as a unique, non-enzymatic electrochemical sensor for future medical applications.
•We present an efficient, and cost-effective approach to produce highly sensitive non-enzymatic electrochemical biosensor for l-Cysteine and H2O2 detection.•Hybrid TiO2 nanotubes (H-TNTs) arrays, consisting a nanoporous layer at the tube openings, were prepared via anodization in residual electrolyte.•The excellent selectivity of H-TNTs for detection of both analyte and stability study illustrates its potential use in real physiological conditions.•The DFT studies indicates a stronger interaction of the L-Cyst and H2O2 with the H-TNTs by forming stronger covalent bond and intermolecular H-bond.•The DOS analysis revealed that L-Cyst and H2O2 adsorption causes larger Egap reduction which varifiesstronger affinity of H-TNTs towards both molecules.
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