Publications

Metal nanoparticles decorated sodium alginate‑carbon nitride composite beads as effective catalyst for the reduction of organic pollutants

CCDC 1876454: 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.

Fabrication of EPYR/GNP/MWCNT carbon-based composite materials for promoted epoxy coating performance

The present study is aimed to fabricate composite materials containing epoxy resin (EPYR) reinforced by mixed carbon-based nano-fillers in the form of graphene nano-platelet (GNP) and multi-walled carbon nanotube (MWCNT) using the dissolution casting technique with the help of ultrasonic assistance. The pure epoxy resin was reinforced by variable loading of mixed GNP/MWCNT <i>in situ</i>, and the epoxy resin is denoted as EPYR/GNP/MWCNT_2-30. The numbers 2-30 corresponded to the final mass ratio of the nano-fillers. The designed products were reinforced by variable percentages of GNP/MWCNTs. XRD, FT-IR, thermal analyses, FE-SEM, TEM and electrical conductivity were utilized as identification techniques to confirm the structures of these composite materials. An excellent evidence for the composite formation was given by XRD diffraction patterns and FT-IR spectroscopy. The introduced amounts of mixed nano-fillers showed significant effects on the thermal, conducting and coating behaviors of pure EPYR. Pure EPYR and EPYR/GNP/MWCNT_20,30 showed higher thermal stabilities than other materials in the range of 400-410 °C. EPYR/GNP/MWCNT₂₀ also showed remarkable increase in the thermal stability compared to other materials. <i>T</i> ₁₀ represents the temperatures at which 10% weight losses are examined. Pure EPYR and its related EPYR/GNP/MWCNT_2-30 displayed similar thermal stabilities at <i>T</i> ₁₀ temperature (330 ± 4 °C). The morphological features were examined by SEM and TEM; these features showed that the nanocomposite components were extremely compatible. The <i>in situ</i> electrical conductivity values showed noticeable enhancement for the formulations of EPYR/GNP/MWCNT_2-10. Moreover, the coating performance of EPYR was tested by water uptake experiments and electrochemical impedance; both tests proved that the mixed GNP/MWCNT nano-fillers remarkably improved the pure EPYR coating due to the ionic charge transfer resistance and elevated barrier behaviour. The coating resistance variations values (CRv) of EPYR/GNP/MWCNT₁₀ were the highest among the measured composition values, closely followed by those of EPYR/GNP/MWCNT₂₀ and EPYR/GNP/MWCNT₃₀.

Synthesis, characterization and DFT study of methoxybenzylidene containing chromophores for DSSC materials

Chitosan@Carboxymethylcellulose/CuO-Co2O3 Nanoadsorbent as a Super Catalyst for the Removal of Water Pollutants

In this work, an efficient nanocatalyst was developed based on nanoadsorbent beads. Herein, carboxymethyl cellulose-copper oxide-cobalt oxide nanocomposite beads (CMC/CuO-Co₂O₃) crosslinked by using AlCl₃ were successfully prepared. The beads were then coated with chitosan (Cs), Cs@CMC/CuO-Co₂O_3. The prepared beads, CMC/CuO-Co₂O₃ and Cs@CMC/CuO-Co₂O₃, were utilized as adsorbents for heavy metal ions (Ni, Fe, Ag and Zn). By using CMC/CuO-Co₂O₃ and Cs@CMC/CuO-Co₂O₃, the distribution coefficients (K_d) for Ni, Fe, Ag and Zn were (41.166 and 6173.6 mLg^-1), (136.3 and 1500 mLg^-1), (20,739.1 and 1941.1 mLg^-1) and (86.9 and 2333.3 mLg^-1), respectively. Thus, Ni was highly adsorbed by Cs@CMC/CuO-Co₂O₃ beads. The metal ion adsorbed on the beads were converted into nanoparticles by treating with reducing agent (NaBH₄) and named Ni/Cs@CMC/CuO-Co₂O₃. Further, the prepared nanoparticles-decorated beads (Ni/Cs@CMC/CuO-Co₂O₃) were utilized as nanocatalysts for the reduction of organic and inorganic pollutants (4-nitophenol, MO, EY dyes and potassium ferricyanide K₃[Fe(CN)₆]) in the presence of NaBH₄. Among all catalysts, Ni/Cs@CMC/CuO-Co₂O₃ had the highest catalytic activity toward MO, EY and K₃[Fe(CN)₆], removing up to 98% in 2.0 min, 90 % in 6.0 min and 91% in 6.0 min, respectively. The reduction rate constants of MO, EY, 4-NP and K₃[Fe(CN)₆] were 1.06 × 10^-1, 4.58 × 10^-3, 4.26 × 10^-3 and 5.1 × 10^-3 s^-1, respectively. Additionally, the catalytic activity of the Ni/Cs@CMC/CuO-Co₂O₃ beads was effectively optimized. The stability and recyclability of the beads were tested up to five times for the catalytic reduction of MO, EY and K₃[Fe(CN)₆]. It was confirmed that the designed nanocomposite beads are ecofriendly and efficient with high strength and stability as catalysts for the reduction of organic and inorganic pollutants.

CCDC 987762: 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.

Mixed-metal or mixed-linker metal organic frameworks as heterogeneous catalysts

This review illustrates the recent developments in heterogeneous catalysis using mixed metal or mixed linker MOFs.

In vitro studies of carbon fiber microbiosensor for dopamine neurotransmitter supported by copper-graphene oxide composite

Novel photochromic system derived from tetracyanoquinodimethane and pyrazoles

Purpose To discover new photochromic molecules suitable for various applications. Design/methodology/approach The synthesis of the new photochromic pyrazole derivatives was accomplished by reaction of tetracyanoquinodimethane (TCNQ) and pyrazoles in polar solvents such as dimethylformamide (DMF). Findings A new photochromic system had been developed and the synthesis and photochromic properties of three pyrazole derivatives upon irradiation with ultraviolet light were studies in different solvents. The photochromic and thermochromic properties were affected markedly upon changing the solvent polarity. The new materials gave colourless to deep yellow coloration upon irradiation with ultraviolet, rendering them suitable candidates for optical storage media using the region of 400 nm. Practical implications A new photochromic system had been developed via a simple method. The new compounds showed photochromic, thermochromic, and solvatochromic properties making them potential candidates for many applications such as sensors, optical data storage, sensors and heat sensitive materials. Originality/value The photochromic system was novel and hence the photochromic molecules were novel.

Sonocatalytic Degradation of Malachite Green Dye Using Green Synthesized Copper Oxide Nanoparticles

Synthesis, Structure, and Properties of Near‐Infrared [<i>b</i>]Phenanthrene‐Fused BF₂ Azadipyrromethenes

A new class of phenanthrene-fused BF₂ azadipyrromethene (azaBODIPY) dyes have been synthesized through a tandem Suzuki reaction and oxidative ring-fusion reaction, or a palladium-catalyzed intramolecular C-H activation reaction. These phenanthrene-fused azaBODIPY dyes are highly photostable and display markedly redshifted absorption (up to λ=771 nm) and emission bands (λ≈800 nm) in the near-infrared region. DFT calculations and cyclic voltammetry studies indicate that, upon annulation, more pronounced stabilization of the LUMO is the origin of the bathochromic shift of the absorption and high photostability.

CCDC 877203: 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.

CCDC 987765: 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.

Mechanochemische Bildung von Gold(III)‐Kohlenstoffbindungen

Abstract Ausgehend von einem [( MeO C^N^C)AuCl]‐Komplex als Vorstufe wurde eine direkte Substitution durch C,H‐Aktivierung von sp‐, sp 2 ‐ oder sp 3 ‐C,H‐Bindungen unter basischen Bedingungen in einer Planetenkugelmühle erreicht. Aufgrund der außergewöhnlichen photophysikalischen Eigenschaften der Zielverbindungen bietet dieses Verfahren einen einfachen Zugang zu einer wertvollen Klasse von Komplexen. Im Gegensatz zu zuvor bereits bestehenden Verfahren, erfordert dieses keine Vorfunktionalisierung der Ausgangsmaterialien und die Verwendung teurer Übergangsmetallkatalysatoren kann vermieden werden, was diese Anwendung auch für industrielle Zwecke attraktiv macht. Darüber hinaus war die Methodik nicht auf Pincer‐Komplexe beschränkt, was durch die Substitution von Chelat‐Typ [(tpy)AuCl 2 ]‐Komplexen gezeigt wurde.

Can Short- and Middle-Range Hybrids Describe the Hyperpolarizabilities of Long-Range Charge-Transfer Compounds?

The hyperpolarizabilities of five prototypical and four recently synthesized long-range charge-transfer (CT) organic compounds are calculated using short- and middle-range (SR and MR) hybrid functionals. These results are compared with data from MP2 and other DFT methods including GGAs, global hybrids, long-range corrected functionals (LC-DFT), and optimally tuned LC-DFT. Although it is commonly believed that the overestimation of hyperpolarizabilities associated with CT excitations by GGA and global hybrid functionals is the result of their wrong asymptotic exchange potential, and that LC-DFT heals this issue, we show here that SR and MR functionals yield results similar to those from LC-DFT. Hence, the long-range correction per se does not appear to be the key element in the well-known improved description of hyperpolarizabilities by LC-DFT. Rather, we argue that the inclusion of substantial amounts of Hartree-Fock exchange, which reduces the many-electron self-interaction error, is responsible for the relatively good results afforded by range separated hybrids. Additionally, we evaluate the effects of solvent and frequency on hyperpolarizabilities computed by SR and MR hybrids and compare these predictions with other DFT methods and available experimental data.

Bilirubin sensor based on CuO-CdO composites deposited in a nafion/glassy carbon electrode matrixes

Copper oxide-cadmium oxide nanocomposites (CuO-CdO NCs) were synthesized by solvothermal technique in a basic medium. CuO-CdO NCs were characterized using conventional techniques, such as Fourier Transform Infrared Spectroscopy (FTIR), UVâVisible Spectroscopy (UV/Vis), Field-Emission Scanning Electron Microscopy (FESEM), X-ray electron dispersive spectroscopy (XEDS), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffraction (XRD). A selective and enzyme-less Bilirubin (BLR) sensor was developed with a thin-layer of NCs onto a glassy carbon electrode (GCE, surface area = 0.0316 cm2) using 5% nafion binders at room conditions. Improved electrochemical performances of higher sensitivity, lower detection limit, linear dynamic range (LDR), and long-term stability of preferred BLR were achieved by a reliable current-voltage (I-V) approach. The calibration curve was found linear (R2 = 0.9347) in a wide range of BLR concentration (10.0 pM ~ 10.0 mM). Based on the signal to noise ratio value of 3, the sensitivity and limit of detection (LOD) of the sensor were calculated as 95.0 pA μMâ1 cmâ2 and 1.0 ± 0.1 pM respectively. Solvothermally synthesized CuO-CdO NCs/GCE is an excellent advancement of developing a selective and sensitive BLR sensor by electrochemical approach and practically implemented in real sample applications. Keywords: CuO-CdO nanocomposites, Bilirubin biosensor, Glassy carbon electrode, Sensitivity, Real sample analysis, Health care field

Nanophotocatalysis and Environmental Applications

Sustainable Agriculture Reviews 37