Publications

Recent Advances in 1D Electrospun Nanocatalysts for Electrochemical Water Splitting

Electrochemical water splitting, as a promising sustainable‐energy technology, has been limited by its slow kinetics and large overpotential. This shortcoming necessitates the design of 1D nanocatalysts with large surface area, high electronic conductivity, and easily tunable composition. Herein, recent progress about electrocatalytic water splitting based on the advanced electrospun nanomaterials is reviewed. First, the related fundamentals of electrochemical water splitting according to two main aspects are discussed as follows: hydrogen evolution reaction and oxygen evolution reaction. Second, the structure design and the electrocatalytic properties of electrospun nanomaterials according to difference in component (including single metal‐based electrocatalysts, metal alloy‐based electrocatalysts, metal oxide‐based electrocatalysts, metal sulfide‐based electrocatalysts, metal phosphide‐based electrocatalysts, metal carbide‐based electrocatalysts, etc.) are summarized. Finally, the future perspectives and challenges for designing next‐generation 1D electrospun nanocatalysts for electrochemical water splitting are concluded.

Microwave Assisted Synthesis, Spectrofluorometric Characterization of Azomethine as Intermediate for Transition Metal Complexes with Biological Application

Removal of a melamine contaminant with Ag-doped ZnO nanocomposite materials

In this approach, Ag-doped ZnO nanosheets (Ag/ZnO NSs) were prepared <italic>via</italic> a facile wet-chemical method using reducing agents in an alkaline medium at a low temperature.

Synthesis and photophysical studies on a new fluorescent phenothiazine‐based derivative

A new typical phenothiazine compound functionalized with thienyl-indandione derivative (PTZTID) was synthesized and characterized using spectral analysis (ultraviolet-visible (UV-vis) light, infrared (IR), ¹ H nuclear magnetic resonance (NMR) and ¹³ C NMR tools). The UV-vis absorption spectra of the PTZTID solution in 1,4-dioxane showed two absorption bands attributed to localized aromatic π-π* transitions of conjugated aromatic moieties and intramolecular charge transfer with the characteristics of a π-π* transition. The fluorescence spectra exhibited a maximum emission wavelength at 580 nm. The effect of concentration on photophysical properties took the form of a minor hypsochromic shift, which was attributed to some extent to the occurrence of H-type aggregation of the PTZTID derivative. Binary solvent effects on the spectroscopic behaviour of PTZTID were measured at different H₂ O/1,4-dioxane ratios. Similarly, when increasing the water content, a hypsochromic shift was observed that resulted from H-type aggregation. Furthermore, geometry and electronic configurations of PTZTID were studied at density functional theory /B3LYP level and indicated that the compound had a nonplanar (butterfly structure).

Recent Advances, Challenges, and Future Perspectives of ZnO Nanostructure Materials Towards Energy Applications

In this approach, zinc oxide (ZnO) is a multipurpose substance with remarkable characteristics such as high sensitivity, a large specific area, non-toxicity, excellent compatibility, and a high isoelectric point, which make it attractive for discussion with some limitations. It is the most favorable possible option for the collection of nanostructures in terms of structure and their characteristics. The development of numerous ZnO nanostructure-based electrochemical sensors and biosensors used in health diagnosis, pharmaceutical evaluation, food hygiene, and contamination of the environment monitoring is described, as well as the production of ZnO nanostructures. Nanostructured ZnO has good chemical and temperature durability as an n-type semiconducting material, making it useful in a wide range of uses, from luminous materials to supercapacitors, batteries, solar cells, photocatalysis, biosensors, medicinal devices, and more. When compared to the bulk materials, the nanosized materials have both a higher rate of disintegration and a higher solubility. Furthermore, ZnO nanoparticles are regarded as top contenders for electrochemical sensors due to their strong electrochemical behaviors and electron transmission characteristics. The impact of many factors, including selectivity, sensitivity, detection limit, strength, and structures, arrangements, and their respective functioning processes, has been investigated. This study concentrated a substantial amount of its attention on the recent advancements that have been made in ZnO-based nanoparticles, composites, and modified materials for use in the application areas of energy storage and conversion devices as well as biological applications. Supercapacitors, Li-ion batteries, dye-sensitized solar cells, photocatalysis, biosensors, medicinal, and biological systems have been studied. ZnO-based materials are constantly analyzed for their advantages in energy and life science applications.

Resonance Light-Scattering Enhancement Effect of the Y(III)–PUFX–Eosin System and its Fluorescence Study

(<i>Z</i>)-2-Sulfanylidene-5-(thiophen-2-ylmethylidene)imidazolidin-4-one

The mol-ecule of the title compound, C(8)H(6)N(2)OS(2), has a V shape with two five-membered rings attached to a methyl-ene C atom. All non-H atoms are approximately coplanar (r.m.s. deviation = 0.096 Å). In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into layers. The thio-phene ring is disordered over two positions; the major orientation has an occupancy of 0.683 (3). is there an intramolecular N---H...S bond?

Prevalence of Osteoporosis and Osteopenia among Cancer Patients and Its Risk Factors: A Retrospective Analysis at Najran Cancer Center, Saudi Arabia

Objective: The assessment of bone mineral density (BMD) in patients with a higher risk for significant bone loss, such as cancer patients, was recommended by recent clinical guidelines. Herein, we aim to report the prevalence of osteoporosis and osteopenia and their associated factors in cancer patients.Methods: This retrospective cross-sectional study was conducted from February 2021 to March 2022, and it included 39 adult cancer patients who were being treated at the King Khalid Hospital Cancer Center in Najran, Saudi Arabia. The participants were interviewed, and their BMD was assessed using Dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine and femur neck. Univariate analysis was carried out to examine the association between osteoporosis and osteopenia and other variables. Results: The study involved 39 adult cancer patients in Najran, Saudi Arabia with a mean age of 60.15 ± 12.26 years, the majority of patients (53.8%) were aged between (60-69) years old, and most of them (64.1%) were female. The primary diagnosis was mostly breast cancer (35.9%) followed by prostate cancer (25.6%). 66.7% received chemotherapy and 64.1% received hormone therapy. Results showed osteopenia, osteoporosis, and normal BMD in 7 (17.9%), 28 (71.8%), and 4 (10.3%) patients respectively. 43.6% had low serum vitamin D levels. There was no significant relationship between osteopenia/osteoporosis and various factors, but it was more frequent in older patients, those undergoing chemotherapy, and those with low vitamin D levels (p=0.04, 0.05, 0.005). Conclusion: Higher prevalence of osteoporosis and osteopenia were observed in cancer patients undergoing chemotherapy, older patients, and those with low vitamin D levels. Further research is necessary to determine the most effective strategies for minimizing bone loss in this population.

Detection of 3,4-diaminotoluene based on Sr_0.3Pb_0.7TiO₃/CoFe₂O₄ core/shell nanocomposite <i>via</i> an electrochemical approach

We reported a scalable sol–gel method for the preparation of Sr_0.3Pb_0.7TiO₃/CoFe₂O₄ core–shell magnetic nanocomposite with a finely controlled shell and evaluated its efficiency as an electrochemical sensor for the selective detection of 3,4-diaminotoluene.

CCDC 877299: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Single‐Particle Spectroscopy on Large SAPO‐34 Crystals at Work: Methanol‐to‐Olefin versus Ethanol‐to‐Olefin Processes

The formation of hydrocarbon pool (HCP) species during methanol-to-olefin (MTO) and ethanol-to-olefin (ETO) processes have been studied on individual micron-sized SAPO-34 crystals with a combination of in situ UV/Vis, confocal fluorescence, and synchrotron-based IR microspectroscopic techniques. With in situ UV/Vis microspectroscopy, the intensity changes of the λ=400 nm absorption band, ascribed to polyalkylated benzene (PAB) carbocations, have been monitored and fitted with a first-order kinetics at low reaction temperatures. The calculated activation energy (Ea ) for MTO, approximately 98 kJ mol(-1) , shows a strong correlation with the theoretical values for the methylation of aromatics. This provides evidence that methylation reactions are the rate-determining steps for the formation of PAB. In contrast for ETO, the Ea value is approximately 60 kJ mol(-1) , which is comparable to the Ea values for the condensation of light olefins into aromatics. Confocal fluorescence microscopy demonstrates that during MTO the formation of the initial HCP species are concentrated in the outer rim of the SAPO-34 crystal when the reaction temperature is at 600 K or lower, whereas larger HCP species are gradually formed inwards the crystal at higher temperatures. In the case of ETO, the observed egg-white distribution of HCP at 509 K suggests that the ETO process is kinetically controlled, whereas the square-shaped HCP distribution at 650 K is indicative of a diffusion-controlled process. Finally, synchrotron-based IR microspectroscopy revealed a higher degree of alkylation for aromatics for MTO as compared to ETO, whereas high reaction temperatures favor dealkylation processes for both the MTO and ETO processes.

Pyran-Squaraine as Photosensitizers for Dye-Sensitized Solar Cells: DFT/TDDFT Study of the Electronic Structures and Absorption Properties

In an effort to provide, assess, and evaluate a theoretical approach which enables designing efficient donor-acceptor dye systems, the electronic structure and optical properties of pyran-squaraine as donor-acceptor dyes used in dye-sensitized solar cells were investigated. Ground state properties have been computed at the B3LYP/6-31+<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:msup><mml:mrow><mml:mtext>G</mml:mtext></mml:mrow><mml:mrow><mml:mi>*</mml:mi><mml:mi>*</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math>level of theory. The long-range corrected density functionals CAM-B3LYP, PBEPBE, PBE1PBE (PBE0), and TPSSH with 6-311++<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:msup><mml:mrow><mml:mtext>G</mml:mtext></mml:mrow><mml:mrow><mml:mi>*</mml:mi><mml:mi>*</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math>were employed to examine absorption properties of the studied dyes. In an extensive comparison between experimental results and ab initio benchmark calculations, the TPSSH functional with 6-311++<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:msup><mml:mrow><mml:mtext>G</mml:mtext></mml:mrow><mml:mrow><mml:mi>*</mml:mi><mml:mi>*</mml:mi></mml:mrow></mml:msup></mml:mrow></mml:math>basis set was found to be the most appropriate in describing the electronic properties for the studied pyran and squaraine dyes. Natural transition orbitals (NTO), frontier molecular orbitals (FMO), LUMO, HOMO, and energy gaps, of these dyes, have been analyzed to show their effect on the process of electron injection and dye regeneration. Interaction between HOMO and LUMO of pyran and squaraine dyes was investigated to understand the recombination process and charge-transfer process involving these dyes. Additionally, we performed natural bond orbital (NBO) analysis to investigate the role of charge delocalization and hyperconjugative interactions in the stability of the molecule.

Fabrication of a 2,4-dinitrophenol sensor based on Fe₃O₄@Ag@Ni nanomaterials and studies on their antibacterial properties

Scheme representing (a) MO coated GCE, (b) theoretical <italic>I</italic>–<italic>V</italic> response, (c) observed <italic>I</italic>–<italic>V</italic> responses by the MO/Nafion/GCE, and (d) proposed detection mechanism of 2,4-DNP.

CCDC 870851: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Large-scale Synthesis of Low-dimension Un-doped Iron Oxide Nanoparticles by a Wet-Chemical Method: Efficient Photo-catalyst &amp; Sensitive Chemi-sensor Applications

Iron oxide nanoparticles (NPs) have been prepared in large-scale by wet-chemical method (150.0 oC and pH 8.33) using ferric chloride and urea as a starting materials in aqueous-alkaline medium. The structural, physical, and optical properties are characterized using FT-IR, UV–vis spectroscopy, Raman spectroscopy, powder X-ray diffraction, Fieldemission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and Electron diffraction system (EDS). The NPs size (average dia. 45 ± 5 nm) was measured by FE-SEM while the single phase of NPs were exemplified using powder X-ray diffraction technique. As-grown nanoparticles were applied for the photocatalytic degradation using acridine orange (ACR) and chemical sensing of aqueous ammonia. Almost 58.38% degradation with ACR was observed in presence of nanoparticles under UV sources (250 W). The silver electrode (AgE, surface area, 0.0216 cm2) was immobilized with NPs which enhanced ammonia-sensing performances in their electrical response (I-V characterization) for detecting and quantifying the ammonia in aqueous system. The analytical performances of NPs sensor were investigated that the sensitivity and stability of the sensor improved extensively using NPs thin-film on active silver surface. The calibration plot was linear (R =0.9337) over the large range of 5.0 μM to 0.5 M. The sensitivity was calculated as 4.6154 μAcm-2mM-1 with detection limit (2.5±0.2 μM), based on a signal/noise ratio (3N/S). This study has introduced a novel way for efficient chemical sensor development as well as active photo-catalyst using low-dimensional NPs for the detection of environmental carcinogenic and hazardous compounds. Keywords: Iron oxide nanoparicles, Chemi-sensors, Sensitivity, Solution method, Optical properties

Synthesis and Biological Evaluation of New N,N′‐Bis(1‐substituted‐ethylidene)‐ethane1,2‐diamine and Their Acetyl and Trifluoroacetyl Derivatives as Cytotoxic and Antimicrobial Agents

Several Schiff bases 2 have been prepared by the condensation of various methyl ketones 1 with 1,2‐ethylenediamine. Subsequent acylation of these Schiff bases with trifluoroacetic anhydride in THF yields the corresponding trifluoroacetyl derivatives 3 . However, o ‐hydroxy‐ and o ‐methoxy‐substituted derivatives yielded substituted‐trifluoromethylchroman‐4‐ones. Additionally, Schiff bases when reacted with acetic anhydride afforded the C‐acetylated derivatives 4 . The structures of the isolated compounds were fully determined by spectral methods. Preliminary biological screening of the prepared compounds revealed significant cytotoxic and antimicrobial activities.

Chitosan hydrogel wrapped bimetallic nanoparticles based efficient catalysts for the catalytic removal of organic pollutants and hydrogen production

A novel catalytic system based on bimetallic nanoparticles entrapped chitosan hydrogel container (Cu–Ag/CH, Cu–Co/CH, Cu–Ni/CH) was prepared. The developed catalytic system was applied for production of H 2 from water and methanol and reduction of 4‐nitrophenol (4‐NP), 3‐nitrophenol, 2‐nitrophenol, 2,6‐dinitrophenol, methylene blue, congo red (CR), methyl orange, acridine orange, and potassium ferricynide (K 3 [Fe(CN) 6 ]). The developed catalytic system has shown tremendous performance and exhibited high efficiency as a catalyst for water treatment and H 2 generation. Among all the nanocatalysts, Cu–Co/CH was more efficient in catalytic H 2 generation while Cu–Ni/CH was more efficient in catalytic reduction of toxic contaminants. Further, various parameters like amount of NaBH 4 , catalyst quantity, pollutant concentration, and temperature were optimized to enhance the effectiveness of catalytic system for fast production of H 2 and reduction of toxins. Moreover, the recyclability of the catalyst was investigated, where slight decrease in reduction time was noted.

Arylnaphthalene lactone analogues: synthesis and development as excellent biological candidates for future drug discovery

Arylnaphthalene lactones are natural products extracted from a wide range of different parts of plants. The progressing interest in the synthesis of these compounds is due to their significant biological activities, which have made them potential candidates in drug discovery and development. This review mainly covers recent developments in the synthesis and biological applications of arylnaphthalene lactone analogs.