2022-05

Scientfic Journal university of zakho

In this study, the gold (Au) noble metal doped Ag3PO4 nanoparticles (NPs) were synthesized by hydrothermal method. The obtained photocatalysts NPs were characterized via FE-SEM, EDX, XRD and UV-Vis spectrophotometer. The crystal structure and phase were identified by XRD characterization. From the XRD the structure of Ag3PO4 NPs was not altered after doping with Au as a noble metal; in addition the sharp and narrow peaks indicate that Ag3PO4 NPs are high purity and have a crystalline structure. And the XRD pattern of samples after doping indicates that Au distributed homogenously in Ag3PO4. The morphology of bare Ag3PO4 and Au doped Ag3PO4 were studied by FE-SEM. The average sizes of the synthesized Ag3PO4 and Au doped Ag3PO4 NPs were 747.81 nm and 96.77nm respectively. EDX is utilized for the elemental composition analysis of the synthesized NPs and the pattern consists of corresponding peaks for P, Ag, O, and Au ions and it confirms the doped of Au noble metal ion in the prepared samples . The optical properties and the band gap were estimated by UV-Vis spectrophotometer. The band gap was found for undoped and doped Ag3PO4 NPs were 2.39 eV and 2.34 eV respectively. Furthermore, the photocatalytic performances for bare Ag3PO4 NPs and Au doped Ag3PO4 were studied with fast green FCF dye. As a result the Au@ Ag3PO4 could be considered the optimum photocatalyst because the target dye molecule is degraded in 15 min, in contrast the bare Ag3PO4 NPs needed 55min. The photo degradation rate of the Au@ Ag3PO4 NPs is ∼3 times higher than the rate of Ag3PO4 NPs. Finally, Au@ Ag3PO4 NPs confirmed the highest photodegradation catalyst compared with other bare Ag3PO4 NPs.

2021-02

Anthropocene Coasts (Issue : 6) (Volume : 4)

Abstract: Coastal environments are subject to trace metal pollution via a combination of industry and urbanised sources. The pollutants accumulate within surface sediments, especially in the quieter backwaters of estuaries. An environmental assessment of the Port Hacking estuary, southern Sydney, Australia, was undertaken using 233 surface samples. Trace metal concentrations (Ni, Cr, Cu, Zn, Pb, and As) in these samples indicated that most elements in Port Hacking were below the relevant ANZECC/ARMCANZ guideline low trigger value (ISQG-low), but a few sites exceeded this value. The low trace metal concentrations are mainly because the catchment areas have limited urban development and few discharge points. In contrast, one site in Gunnamatta Bay has Zn and Cu concentrations that exceeded the high trigger value (ISQG-high), due to moored vessels, boatyards, and stormwater outlets in this vicinity. Port Hacking is considered to be relatively unpolluted and healthy when compared with other Sydney estuaries.

2020-12

Science Journal of University of Zakho (Issue : 4) (Volume : 8)

In this study, the atomic absorption spectrophotometer (AAS) technique has been used in analysing 26 soil samples for five heavy metals: Pb2+, Cu2+, Zn2+, Cr3+ and Ni2+ in Zakho district, Kurdistan region - Iraq. Heavy metals can be accrued to the soil during the releases of industrial waste, removal of extraordinary quality metal waste, petrochemical falls and etc. In all soil samples, heavy metals concentration was found in the range of 0.541 - 4.339 mg/L for Pb, 0.118 - 0.797 mg/L for Cu, 1.260 - 5.540 mg/L for Zn, 1.315 - 2.102 mg/L for Cr and 1.049 -1.635 mg/L for Ni. As shown in the result, the heavy metals concentration contents increases with fossil fuel combustion, industrial releases, and agricultural activities. However, the results of the AAS technique was found that the high concentration element Pb and Zn were determined than the other elements like Cu, Cr and Ni but less than acceptable limits in all cases. Regarding to achieve data in the recent research, soil

2020-04

ORIENTAL JOURNAL OF CHEMISTRY (Issue : 2) (Volume : 36)

Due to the largely and an efficient usage of Weinreb amides or N-methoxy-N-methylamides as are remarkable intermediate in the organic synthesis field, the recent review paper provides a considerable development literature survey on the Weinreb amides synthesis. The direct transformation of carboxylic acids,acid chlorides, and esters to aldehydes or ketones employing organometallic reagents do not lead in high yields, since the high reactivity of ketone intermediates toward the organometallic reagents. While, the conversion to the appropriate Weinreb Amides, followed by treatment with the organometallic regent, result the stable expected ketones as the stable initial adduct toward further reactions. Furthermore, Weinreb amides undergo nucleophilic addition and produce a unique and steady five-membered cyclic intermediate which protects the over-addition, leading to a serious transformation.

2020-02

Digest Journal of Nanomaterials and Biostructures (Issue : 1) (Volume : 15)

Using a microwave-assisted hydro thermal method (MWAHM) a single crystalline of vertically aligned TiO2 nanorod (NR) arrays has been achieved via the novel ultra-rapid synthetic method for the production. High-quality NR arrays with controlled film thickness were achieved with fine control of the growth conditions as well. The effect of the different reaction conditions of MWAHM such as reaction time and growth temperature on the morphology, crystal orientation, and photo catalytic activity have been systematically investigated. In a typical condition of the MWAHM using 0.4 cm3 of titanium(IV) n-butoxide (TBO) at 180 °C for 40 minutes, a small diameter of 124 nm and short length 2.93 μm of TiO2 nanorods, are grown on fluorine-doped tin oxide (FTO) substrate. However, the photo current density produced TiO2 NRs of 2.90 mA cm-2 with a maximum photo conversion efficiency of about 2.7% which confers excellent photoelectrochemical performance. In comparison with the typical hydro thermal method (HM) synthesized NRs, the ultra-fast MWAHM synthesized NRs offers five times more efficiency photoelectrochemical (PEC) water splitting than the hydro thermal method (HM). The results suggest that these dense and aligned one-dimensional TiO2 nanorods are promising for hydrogen generation from water splitting based on PEC cells

2019-12

ORIENTAL JOURNAL OF CHEMISTRY (Issue : 6) (Volume : 35)

N-methoxy-N-methyl amides or Weinreb amides are worthy embranchment of amide group and their rich functional groups in organic synthesis become a strong else unfeasible conversion. Weinreb amides are produced as an intermediate product of the reaction of carboxylic acids, acid chloride or esters with organometallic reagents, which was first uncovered in 1981. The direct conversion of carboxylic acids or acid chlorides or esters to ketones or aldehydes using organometallic reagents do not lead in high yields, because the intermediate ketones are still highly reactive toward the organometallic reagent. However, after derivatization to the corresponding Weinreb amide, reaction with organometallics does give the desired ketones, as the initial adduct is stabilized and doesn't undergo further reactions. A nucleophilic addition to the Weinreb amides results in a unique and stable five-membered cyclic tetrahedral intermediate which protects the over-addition, leading to a selective conversion.

2019-02

IOP Conference Series: Materials Science and Engineering (Issue : 5) (Volume : 452)

Bromopyrogallol Red (BPR) as analytical reagent has been used for simultaneous determination of iron and calcium using first-derivative spectrophotometry. The zero - crossing technique was employed using first-derivative for Fe-BPR and Ca-BPR at 600 nm and 558 nm respectively. The linear relationship for Fe and Ca determination obeys beer's law from 0.2-1.2 μg/ml and 0.2-1.0 μg/ml respectively. The proposed method should be useful for accurate, precise, and rapid determination of iron and calcium in various samples with percentage recovery of about 101%. The stability constants (mean of three values) were found to be 1.33×108 L2.mol-2 and 9.13 × 1011 L2.mol-2 for Fe-BPR and Ca-BPR complexes respectively which indicates that the complexes are stable.

2018-12

International Journal of Advanced and Applied Sciences (Issue : 12) (Volume : 3)

Dithio based chelating ionophores such as 1-anilino-6-(3, 4-xylyl)-2, 5- dithiobiurea (A) and Dithiodiglycolic acid (B) were used as active components of PVC membrane electrode and explored as Cu2+-ion selective electrodes. The membranes having the composition (A): o-nitrophenyl octyl ether (o-NPOE): polyvinyl chloride (PVC): potassium tetrakis(4- chlorophenyl) borate (KTpCIPB) in the ratio of 3: 78: 40: 2 (w/w; mg) and (B): (o-NPOE): (PVC): (KTpCIPB) in the ration 3 :80 :40 :3 are found to be exhibiting the best sensor characteristics. The fabricated sensors exhibited Nernstain response (29.301 and 28.223 mV decade-1) over concentration ranges of 1.0 × 10-8 to 1.0 ×10-1 mol/L and 1.0 × 10-7 to 1.0 ×10-1 mol/L and exhibit detection limit of 2.2 × 10-8 and 8.3 × 10-7 mol /L for sensor No. 9 and 6 for ionophores A and B, respectively. The best performances were observed with the sensor having the composition of (A): (o-NPOE): (PVC): (KTpCIPB) in the ratio of 3: 78: 40: 2 (w/w; mg), and the electrodes have a response time of 9 - 12 s with a pH range of 3.0 - 7.0, and could be used over a period of 3 months without any significant deviation in its potentiometric characteristics. The analytical usefulness of the proposed sensor has been evaluated by its application in the determination of copper in water samples, the results obtained by the proposed ISEs are in good agreement with the results obtained by direct flame AAS method. The sensor No. 9 has been used also in the potentiometric titration of Cu2+ with EDTA.

2018-09

Science journal of university of zakho (Issue : 3) (Volume : 6)

Laurus nobilis (Bay leaf), was examined for its capacity to remove hexavalent chromium Cr(VI) poisonous, from aqueous solution. The bio-adsorbent using bay leaf obtained from Laurus nobilis was investigated in batch experiments. The influence of main parameters such as chromium concentration, pH and shaking time are tests. The effect of beginning concentration of Cr(VI) ion (10 to 50 mg/dm ), pH (1 to 6) and shaking time (5 to 180 min) have been reported. The optimum pH was found to be pH 4.. Results show that the most appropriate model was pseudo second-order kinetic and it correlate with the trial statistics well.

2018-02

IOP Conference Series: Materials Science and Engineering (Issue : 5) (Volume : 454)

Abstract. Undoped and Y doped ZnO nanorods (YZO NRs) were prepared by hydrothermal method. The as-prepared ZnO and YZO NRs with different Y/Zn molar ratios were used as anodes for electrochemical water splitting. Then, photoelectrochemical (PEC) water splitting performances of YZO NRs were tested. When compared with pristine ZnO NRs, the photocurrent density generated with yttrium doped zinc oxide NR as electrode was higher(1.2 mA cm-2 ) than that obtained with pristine ZnO NRs (0.25 mA cm-2), at 0.2 V vs. Ag/ AgCl using samples of 1.2 mol % of yttrium. This performance corresponds to calculated photoconversion efficiency of 0.40%, at a low potential (-0.38V vs Ag/AgCl) of the non-doped ZnO NR film.

2017-03

Science Journal of University of Zakho (Issue : 1) (Volume : 5)

Single crystalline rutile TiO2 nanorods (TNRs) films have been grown on the fluorine doped tin oxide (FTO) substrates using a one pot hydrothermal method, have attracted great attention because of favorable applications in the photoelectrochemical water splitting system. The effect of the reaction conditions on the morphology, crystal orientation and photocatalytic activity has been systematically investigated. The X-ray diffraction (XRD) pattern shows that two diffraction peaks at 36.3° and 63.2° correspond to the (101) and (002) planes of the tetragonal rutile TiO2 nanorod, respectively. The scanning electron microscope (SEM) of the samples indicates that the TiO2 array surface morphology and orientation are highly dependent on the reaction parameters, such as temperature, reaction time and the titanium precursor concentration. In a typical condition of the hydrothermal method at 0.3ml of TBO and 160°C for 3 hr, a small diameter and short length 190 nm and 2.2 μm of TiO2 nanorods respectively, are grown on florien doped tin oxide (FTO) substrate. When synthesized TiO2 nanorods photocatalyst was irradiated under illumination of simulated AM 1.5G solar light (100 mW cm−2) achieves an overall Photocurrent density of 1.80 mA/cm2 with a maximum photoconversion efficiency of ~1.6%. The results suggest that these dense and aligned one-dimensional TiO2 nanorods are promising for hydrogen generation from water splitting based on PEC cells.