Removing MBD Using Fe 2 O 3 NPs Modi � ed by FeCl 3 ( 0 . 1 M and 0 . 3 mM ) With Myrtle Leaf Extract As Environmental Application


 In this study, iron oxide nanoparticles were synthesized using FeCl3 (0.1 M and 0.3 M) with myrtle leaf extract for of methylene blue dye (MBD) degradation under visible light irradiation (100-watt halogen lamp) as environmental application. X-ray diffraction analysis showed the polycrystalline structure of Fe2O3 material with miller indices confirmed the presence of iron oxide with average crystalline sizes (15.59-16.8 nm) synthesized by (0.1M - 0.3mM) concentrations of FeCl3. Field emission-scanning electron microscopy revealed rods-like and spherical shapes of Fe2O3 nanoparticles, with an average particle size of 25 to 67 nm, covered the whole top surface of structure. Moreover, the change of the color of the iron oxide NPs from brown to dark brown enhances the transformation of the properties of the material obtained by adding the biomass which gives the absorbance peaks around 265-350 nm and energy band gaps (3 and 3.7 eV) using UV/VIS spectrometer. The methylene blue degradation efficiencies of Fe2O3 NPs prepared by plant extract and FeCl3 with concentrations (0.1 M and 0.3 mM) were 86.3% after 150 min and 90% after 120 min respectively.

Similar problems are likely to be faced including production of toxic chemicals and using expensive substances in chemical synthesis methods such as sol-gel process [15 and 16] co-precipitation [17],and chemical vapor deposition [18 and 19]. Therefore, some researchers tend to use environmentally friendly and cheaper method in addition to avoiding toxic chemicals and high energy, so as to save energy [20 and 23]. This method is called green synthesis achieved using the biological components molecules including microorganisms, biomolecules, and plants extracts that can reduce nanoparticles and preserve their shape and size. The biosynthesis method follows the bottom-up approach and involves either reduction or oxidation reactions [24 and 26].
Water puri cation from textile dyes is one of the important things to preserve our environment in general and this done by various ways like, adsorption [27], ion-exchange[28], UV treatment [29], ozonation [30], Gamma irradiation [31] and biological method [32]. These days the photo degradation method is considered as highly e cient and easy to apply [33][34][35][36]. But it needs a photo catalyst having high surface area, stability, photocatalytic activity and biocompatibility. Photocatalyst surface modi cation increases the charge separation and lifetime of carriers for reduction of the recombination process to improve the degradation e ciency.

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The aim of this study is a synthesize of iron oxide NPs with different concentration of FeCl 3 using plant leaf extract (myrtle) as reducing/stabilizing agent and studying its photocatalytic e ciency of methylene blue dye degradation.

preparation plant leaves extract
Myrtle plant leaves were chosen to synthesis and improved iron oxide NPs properties. These leaves were chopped, dried for few days and then grinding them into powder. The extract was prepared by adding an amount (1gm) of dried leaves to 50 ml of distilled water and stirred it by magnetic stirrer (at 500 rpm and 80 0 C) for 90 min then the solution was ltered and cooled.

Preparation iron oxide nanoparticles
Two concentrations of FeCl 3 (0.1 M and 0.3 mM) put in 100 ml of distilled water to prepare iron oxide nanoparticles and mixed with myrtle plant extract. The formation of nanoparticles was con rmed by changing the color of precursor solution to dark brown. After that the solution was centrifuged at 3500 rpm for 10 min. Optical properties of solution were obtained by UV-Vis spectroscopy and nally the solution was dried in oven at 300 0 C for 2 hours to produce the nanoparticles powder and become ready to characterize by X-Ray diffraction and FE-SEM. Figure

Characterization
XRD measurements have been examined with Cu-Kα radiation (λ=1.54065 Å) with 2θ that ranged from 20° to 90°, and the crystallite size was calculated using the Debye-Scherer equation [37]: Where K is constant value (0.9) called shape factor, λ is the wavelength of X-ray (0.1541 A 0 ), β is FWHM (full width half maximum intensity of diffraction peak), and θ is the angle of diffraction.

Energy band gap
The energy band gap were estimated by plotting of (αhυ)2 versus photon energy (hυ). The extrapolation of the straight line to (αhυ)2 gives the value of the energy gap about 3.00 eV for iron oxide NPs prepared with concentration 0.1 M of FeCl3 as shown in gure (5A),while the energy band gap value increase to 3.7 eV when prepared the nanoparticles with concentration 0.3 mM of FeCl3 as illustrate in gure (5B).

Degradation of methylene blue dye (MBD)
To study the e ciency of synthesized nanoparticles as a photo catalyst, methylene blue dye prepared in concentration of 0.001 of dye powder in 750 ml of distilled water and adding 0.07 gm of iron oxide NPs to 80 ml of dye. To measure the degradation of MBD, the sample has been kept in dark place for 1 hour with stirring on magnetic stirrer after that keeping it again under irradiation of (100-watt halogen lamp) and measuring the optical absorption of the dye to con rm the degradation.
For nanoparticles prepared with concentration 0.1 M of FeCL3, it has been required 30 min for degradation as shown in gure (6A) with addition of NaOH until the pH of solution reached to 10. After irradiation, 10 ml of suspension was taken every 30 min and centrifuged at 2500 rpm for 15 min. as observe in gure (6B) the degradation is start after 20 min of irradiation without adding NaOH.

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The absorbance of the supernatant was measured by UV/Vis spectrometer by monitoring the absorption maximum at λ = 660 nm to obtain degradation e ciency with time of irradiation from 30 min to 150 min. Figure (7) illustrates the degradation of MB dye is reached to 0.2 after 150 min of irradiation and absorption maximum at λ = 660.
The degradation percentage was determined using the following equation [38]: Where, Cini, C n, Aini and A n are the concentration and absorbance of MB dye before and after exposing to visible light irradiation, respectively.
The e ciency of degradation is found to be 79% after 30 min of irradiation, 82% after 60 min, 86% for 90 min, 86.1% for 120 min and 86.3% after 150 min as shown in gure (8).
Iron oxide nanoparticles prepared with concentration 0.3 mM of FeCl3 exhibits high e ciency as photo catalyst without adding NaOH. Degradation of MB dye obtained by measuring absorbance spectrum as shown in gure (9) the degradation has been measured every 20 min and the absorbance reached to 0.18 after 120 min of irradiation. The e ciency of degradation is found to be 77% after 20 min of irradiation, 79% after 40 min, 84% for 60 min, 87.3% for 80 min, 87.8% after 100 min and 90% for 120 min as shown in gure (10).

Conclusion
Myrtle leave plant extracts has been approved as both reducing and stabilizing agent for synthesize iron oxide nanoparticles. The presence of nanoparticles was con rmed by X-ray diffraction which showed the  UV-Vis spectrophotometer of degradation of MBD under irradiation with iron oxide nanoparticles of (0.3 mM of FeCl3) as photo catalyst.