Eco-Friendly Synthesized of CuO Nanoparticles Using Anchusa strigosa L. Flowers and Study its Adsorption Activity

: Environmentally friendly copper oxide nanoparticles (CuO NPs) were prepared with a green synthesis route via Anchusa strigosa L . Flowers extract. These nanoparticles were further characterized by FTIR, XRD and SEM techniques. Removing of Gongo red from water was applied successfully by using synthesized CuO NPs which used as an adsorbent material. It was validated that the CuO NPs eliminate Congo red by means of adsorption, and the best efficiency of adsorption was gained at pH (3). The maximum adsorption capacity of CuO NPs for Congo red was observed at (35) mg/g. The equilibrium information for adsorption have been outfitted to the Langmuir, Freundlich, Temkin and Halsey adsorption isotherm types. The temperature thermodynamic parameters like ΔG°, ΔH° and ΔS° have been calculated.


Introduction:
Dyes are used drastically in many industries covering by dye homes, textile dyes, and paper printers 1 . A considerable proportion of synthetic dyes are misplaced yearly to waste streams for the duration of textile processing, which subsequently enters the surroundings and causes pollution the environment 2 . Textile dyes have a synthetic origins and complex fragrant molecular structures that make them tough to biodegrade when discharged within the environment. A number of dyes are carcinogenic and mutagenic, like Congo pink dye 3 . The maximum regularly used strategies for the removal of dyes infection from commercial effluents encompass ion exchange, membrane filtration, reverse osmosis, solvent extraction, and adsorption [4][5][6][7][8][9] , but adsorption using numerous nanomaterial's is one of the tremendous methods amongst all the above-stated techniques for the exclusion of contamination from water because of its efficiency, simplicity, and low cost 10 .
Nanomaterial along with metal nanoparticles, a few of the various metal oxides, copper oxide (CuO), and CuO-primarily based nanomaterial's, vital substances which are in large part hired in power, and clinical packages, have won sizable interest for the elimination of dyes from polluted water for environmental remediation because of their excessive performance and low cost 11 . To date, distinct physical and chemical procedures have been mentioned to manufacture copper oxides nanoparticles with distinct size, shape, and morphology. Specifically, nanoparticle synthesis. And the usage of green strategies has gained tremendous attention in the recent years 12 . Green synthesis of metallic and metal oxide NPs using environmentally friendly materials such as plant extracts has gathered much more attention due to the mounting necessity to develop such a technology 13 . Green preparation of diverse metallic oxide nanoparticles using of plant-based substances has also attracted vast attention 14 . Consequently, plant extracts were established as excellent materials for the large-scale, easy, and green synthesis of properly-dispersed metal and metal oxide nanoparticles of managed styles and sizes 15 . The aims of this project are to green synthesis of CuONPs using some flower Anchusa strigosa L. Flowers extract, characterization of synthesized copper oxide nanoparticles CuO NPs, study the factors affecting the green synthesis of CuO NPs and teste the obtained CuO NPs as an adsorptive nanomaterial to purify polluted water from some dyes as well as modelling the experimental results with isotherm and kinetic models.

Materials and Methods:
Congo red is an anionic dye, the sodium salt of 3,3′-([1,1′-biphenyl]-4,4′-diyl) bis(4aminonaphthalene-1-sulfonic acid) C33H22N6NaO6S2 as shown in Fig. 1. Congo red has a molecular weight of 696.7 g mol -1 and purity of 98.99 %. It is soluble water azo dye with a red colloidal solution. Congo red has better solubility in organic solvents. Due to their carcinogenic properties Congo red was abounded 16 . Congo red was formerly used to dye cotton but has been superseded by dyes more resistant to light and to washing. It is still used in histology to stain tissues so they can be looked at under a microscope and as an acid-base indicator because it turns red when it is near an alkali and blue when it is near an acid 17 .

Reagent and materials:
All reagent were used in this work were illustrated in Table 1. 3-Melt the weighted flower flour in distilled water by 200 ml . 4-Leaching solution to take out the extract. 5-Prepare a 20 g Cu(NO3)2 in 100 ml distilled water. 6-We add 160 ml of the extract to the nitrate solution with a burette. 7-We filter the product and dry the incubator producing a brown precipitate, which is copper oxide Nanoparticles, as shown in Scheme 1.

Characterization of copper oxide nanoparticles
FT-IR spectrum of synthesized CuO NPs using the Anchusa strigosa L. flower aqueous extract is shown in Fig. 2. The broad absorption band at 3410 cm -1 was due to the -OH group of melanin, and the broadening of the band was possibly due to the hydrogen bonding of OH groups and amine groups. The peaks at 2928 and 2830 cm -1 were assigned to C-H stretching, and the peak observed at 1708 cm -1 was due to C=C stretching. The peak at 1512 cm -1 was due to N-H and C-N groups. The peak observed at 1365 cm -1 was due to the bending of the O-H of carboxylic acid present in the CuO NP the peak at 550 and 584 cm -1 which are attributable to CuO stretching modes.
XRD analysis of the synthesized CuO NPs by flowers of Anchusa strigosa L. aqueous extract was illustrated in Fig. 3.  more aggregates. This can be due to the coating of different surface functional groups from the appeared extract.

Adsorption activity evaluation
The study was performed using 0.0300g adsorbent surface weight, 25ml Congo Red dye solutions 35 mg/L,this study was performed in the thermal shaker the ( 180 rpm). In each solution, samples were tested by UV-Vis 1800 dual-beam digital a device with a wavelength that corresponds to λmax. This study showed the impact of touch time, CuO NPs dose, acid function, ionic strength, and temperatures were in this study. Thermodynamic studies have made by stages study at the best conditions and at different temperatures were investigated.

Removal %=
Where: , Indicate the starting concentration and equilibrium concentration of residual dye mg/L straight. 19 .

Results and Discussion: Contact Time Effect
By attaing the relationship between osculate time and the efficacy of removing Congo Red using CuO NPs, the equilibrium time was definite, as seen in Fig.5 .The end resulting is leads to equilibrium time of run to after 30min of operation time.

Effect weight of the adsorbent
The operation experiments were conducted using a Different weights between (0.0050-0.0700) g, the dye concentration was initially 35mg/L,Was at 298 K temp. Fig.6. The results we gained indicate that the elimination rate is increases as the weight of the adsorbent surface CuO NPs increases because of the surface area of the increase absorbent material. So the removal percentage attained stable value, which is the saturation of the active sites of CuO NPs, and so 0.0300 g was selected as the best weight for the adsorbent.

Effect of acid function
When examining the effect of acid function on removal rate, the range of acid function values (3, 5, 7, 9 and 1 ) 1 were selected Fig. 7. 35mg/L was taken, which is the dye concentration at the start, then pH laying was taken as in the above range using 0.01N of HCL and NaOH. The result shows that the lowest value of removal in pH 3, that the ratio of elimination increased with increases of the pH 5 until it reached pH 7. After pH 9, there was no marked increase, but there was a decrease in the ratio of elimination. And so acid function 3 pH was selected, conformed, and constant in other experiments.  Form Fig. 8 it can be observed that good adsorption was obtained by using smaller ion volume and less charge.

Effect the Temperature
The study of the impact of change in temperature has been explained to show and understand the adsorption process's nature. Table  contains information   In Table 2. The values of ΔG, ΔS and ∆H since is both negative, then it's spontaneity, exothermic and less random.
Adsorption Isotherm: Fig. 10. shows isothermal Congo Red dye adsorption on surface CuO NPs at acid function 8, temperature (288-318) K,0.0300g from the adsorbing Congo Red ,35mg/L of the Congo Red dye, equilibrium time 30min, this figure pointed that the adsorption stench increases with increasing the concentration of equilibrium for Congo Red.
The isotherms getting from the experiments were identical to S-curve in form at Giles' discretion.

Isotherm Freundlich
Freundlich isotherm pattern of adsorption states that it is multi-layered adsorption across heterogeneous active sites Freundlich isothermal. 22

Temkin Isotherm
It is commonly used in the following way 23 . Q e = β ln + β lnC e ………… 9 Where: AT = the binding constant for equilibrium. β = connected to the adsorption heat 23 . where the curves of Temkin isotherm of Congo Red dye adsorption in Fig .13.

Halsey isothermal
In multi-layered adsorption, the Halsey isothermal model is the very good. The Halsey equation has the following linear form: 24 .
ln = 1 ln 1 ln …………… 12 Where: KH and nH are the Halsey isotherm constants. The graph will be between of lnQe vs. lnCe as shown in Fig .14. The (a, b, RL) for Langmuir constants, (n, KF) for the Freundlich pattern, likewise the Temkin pattern constants (β, AT) and the Halsey isotherm constants KH and nH with linear correlation coefficients shown in Table 3.

Conclusions:
In this research, CuO NPs were prepared from Anchusa strigosa flower extract which is an adsorbent material that removes Congo red dye from water contaminants and industries that contain this dye, both medical and industrial, because this reaction was automatic and exothermic and the best results were obtained in Freundlich and Halsey at 30minutes, at a different temperature range, and the best weight was 0.030g.