Arabian Journal of Chemistry
ISSN : 18785352
Current Publisher: Elsevier BV (10.1016)
Total articles ≅ 3,316
Latest articles in this journal
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.02.003
Abstract:Two Yemeni Aloe(s) have been investigated; the resin from A. perry Baker (APR, Socotran Aloe), and the gel from A. vera (AVG, Saber Yamaniis). LC-MS for APR identified aloin B, aloinoside B/A, homonataloin B and microdontin B/A as the major components, constituting 67.7% w/w of the extract. AVG showed the same pattern of anthrones (19.5% w/w), in addition to the chromones aloesin, aloeresin A, aloeresin D and aloeresin E. Dihydro-isocoumarin glucoside was identified in both Aloe species. Aloe extracts showed high antioxidant activity: DPPH (0.09 & 0.05 mM/g TE), ABTS (0.06 & 0.03 mM/g TE), and FRAP (20.5 & 15.5 mM Fe+2E), for APR & AVG, respectively. The antidiabetic properties was evaluated through inhibition of α-glucosidase enzyme. APR showed inhibitory activity with IC50 0.76 μg/mL higher than AVG (IC50 0.76 mg/mL). Aloin A showed the highest inhibitory activity with IC50 0.34 mg/mL that was higher than acarbose (0.54 mg/mL) the positive control indicating that the activity of Aloe extract is linked to the aloin and other anthrone compounds. These findings highlight the phytochemical profile, antioxidant and potential antidiabetic activity of the Yemeni Aloe species and draw attention to their potential application in food, medicine and cosmetic products.
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.01.015
Abstract:The palm-pruning leaves considered as valuable source for low cost adsorbent materials. Such application, enhance the environmental conditions by reducing the bad effects from un-managed palm-pruning leaves such as spreading insects. Herein, the palm-pruning leaves were treated with by water and acid washing to produce cleaned palm leaves (CPL) and then impregnation with iron(III) chloride and thermally treated to produce palm leaves/iron oxide- nanocomposite (PL/IO-NC). The prepared materials were applied for adsorption of some toxic metal ions from solutions. The original palm-pruning leaves as well as the treated adsorbent were characterized by SEM, EDS, FTIR, XRD. Results showed the formation of spots iron oxide nanoparticles onto the palm-pruning leaves. The efficiency of the treated adsorbent for uptake of Mn(II), Co(II) and Pb(II) was studied in term of kinetic, isotherm and thermodynamic to optimize and evaluate the effectiveness of the palm-pruning leaves treatment. The adsorption data was found to be more comfortable with Second order kinetic-model while the isotherm of Langmuir wasn’t suitable and the adsorption data was in agreement with Freundlich assumption. The values of ΔGo in the range (-5.8 to -3.5 kJ/mol) for Mn(II), (-4.2 to -2.1 kJ/mol) for Co(II), (-3.4 to -2.3 kJ/mol) for Pb(II), confirm the confirm the spontaneous and physical nature of the adsorption process.
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.01.017
Abstract:A green method was developed for the synthesis of CuFe2O4 magnetic nanoparticles using a Neem fruit extract. The prepared nanoparticles with an average size of 19.7nm were used as an effective catalyst for the oxidation of various aryl alkanes in moderate to excellent yields under solvent-free conditions. The catalyst was characterized by powder- XRD, SEM and TEM study. The key advantages of this protocol are simple preparation, a recyclable heterogeneous catalytic system, and benign reaction condition with good to excellent yields with high selectivity toward acid (42-87%).
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.01.022
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.01.020
Abstract:This paper reports the synthesis of reduced oxide (RGO) coated polyaniline (PANi) nanocomposites via in-situ emulsion polymerization and its application as counter electrode for dye sensitized solar cells (DSSCs). The synthesized nanocomposites were systematically characterized through Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform resonance infra-red (FTIR) and Raman spectroscopy indicating the uniform intercalation of polyaniline with reduced graphene oxide. The synergy between RGO and PANi chains owing to the co-doped SDS and H2SO4 leads to the enhanced solubility and improved electrocatalytic activity, that was further confirmed through electrochemical measurements to satisfy the criteria for application as cost effective counter electrode material for scalable DSSC. The fabricated CE was highly transparent and reached the conversion efficiency which is comparable to that of Platinum with a current density of (12.58 mA. cm-2) and (13.11 mA. cm-2) respectively under an illumination of AM 1.5 G (100 mW. cm-2) simulated solar light with an overall photo conversion efficiency of 3.9 %. Thus PANi/RGO based nanocomposites could therefore serve as efficient alternative material to Pt. free CE in DSSC.
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.01.024
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.01.025
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.01.023
Abstract:Iodoform (CHI3) is one of the disinfection by-products (DBPs) that is formed in the pre-oxidation and disinfection processes of drinking water treatment. In this study, Fe(II)-activated persulfate oxidation (Fe2+/PS) was employed to degrade iodoform, the effects of initial reactants concentration, reaction parameters, kinetics model were investigated, and the underlying mechanisms of CHI3 degradation in Fe2+/PS oxidation process was unveiled. The results showed that the mole ratio Fe2+/PS of 1:5, initial PS concentration of 15 μmmol/L, and pH of 3.0 were identified as the optimum operating parameters. In addition, a relatively higher temperature could enhance CHI3 removal and deiodination. The kinetic model has two different reaction steps: a fast one during the first ten minutes of reaction; then followed by a much slower one. Suppression of the reaction by TBA and MeOH showed that the combined effects of SO4-· and ·OH contributed to the degradation of CHI3, but ·OH played a dominant role. The degradation pathways and the products of total liberated iodine species demonstrate that the applicability of the Fe2+/PS oxidation process for CHI3 degradation. These results indicated that the Fe2+/PS oxidation process is an effective advanced oxidation process for CHI3 removal in water treatment.
Arabian Journal of Chemistry; doi:10.1016/j.arabjc.2020.02.001
Abstract:It was for the first time that the complex compound of gallic acid with titanium (IV) salt was used as a precursor to synthesize titania nanotubes. The study was separated into four main sections; (I) synthesizing the complex of titanium with gallic acid, (II) synthesizing anatase and rutile phases through thermal decomposing of the complex, (III) investigating the possibility to synthesize titania nanotubes from the rutile and anatase phases, and (IV) photocatalytic ability of all the nanoparticles. Different methods were applied to analysis, including X-ray diffraction, 1H NMR, FT-IR spectroscopy, elemental analysis, quantum-chemical modeling, Raman spectroscopy, thermal analysis, photoluminescence, BET analysis (to investigate the specific surface activity, total pore volume), EDX, electron microscopy (SEM), acceleration voltages, electrical conductivity, BJH method (to determine average pore diameter), and UV-Vis spectroscopy. We illustrated the possibility of the synthesis of the titania nanotubes from the anatase phase, while rutile phase was not turned to a tube shape. The photocatalytic ability of the obtained nanoparticles was tested by degrading bromophenol blue, as an organic pollutant, under weak light. TiO2 in the form of nanotubes could reduce the concentration of bromophenol blue to 82%, as well as the rutile phase - to 70%, and finally anatase as nan-spheres to 36%.
Arabian Journal of Chemistry, Volume 13, pp 160-170; doi:10.1016/j.arabjc.2017.03.004