Degradation of Organic pollutant by Green Tea Iron Nanoparticles

Eco Friendly green synthesis method with the use of green tea leaves is used in preparation of Iron nano particles in this research. This method is rarely ever used. Green synthesis methods are one of the recently developed environmentally favorable methods. Green process methods indeed play a crucial role in the advancement of nanotechnology by offering several benefits such as minimizing environmental impact and ensuring the safety of both researchers and end-users. Green manufacturing of catalysts supports sustainable advanced oxidation processes for degradation of organic products. Polyphenol contents which are already in plants prepare the metal nano particles and are revived by non-harmful biodegradable chemical components. High temperature and energy is not required in green synthesis method. The are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterized the synthesized nanoparticles. UV-vis spectrophotometer was used for calculating degradation efficiency of Nanoparticles (NPs). Degradation of Methylene Blue (MB) dye was investigated under sunlight with respect to time and catalyst concentration. MB dye was used as a model dye.


INTRODUCTION
Nanotechnology has made significant advancements and has had a profound impact on various aspects of human life in recent years [1][2].The Nanoparticles can be prepared with restrained size, morphology and with enhanced crystalline nature.Therefore, the nanomaterial has tremendous uses in several areas of research [3][4][5].Nanoparticles can be synthesized by many physical and chemical routes as given in literature.However, the usage of Toxic organic pollutant in these methods has harmful effect on environment and cost high, still we achieve the controlled size and shape of nanoparticles, these NPs have restriction in certain biological applications due to toxic compounds present [6].To overcome this drawback researcher focused to develop NPs which are non-toxic, bio-compatible and environment friendly.Moreover, environmental issues today has become reason of concern and forced researchers to find out the new ways for ecofriendly and less toxic methods for the synthesis and application of nanomaterial's, which have lower health risks, easily degradable and can be developed from products which are renewable.Green nanotechnology is good alternate to handle all these issues and green synthesis has become part of this upcoming nanotechnology, which helps in the production of nanomaterial in an eco-friendly manner.Therefore, green synthesis method was adopted for clean, nontoxic and environmentally pure materials NPs.For this method biological plant like fungus, roots, yeast, gum, bacteria's and viruses were used across the world to prepare NPs [7][8][9][10][11].In Green synthesis technique, Natural extracts derived from plants often possess reducing properties, allowing them to facilitate the synthesis of nanoparticles or other materials without the need for conventional reducing agents.These extracts contain bioactive compounds such as polyphenols, flavonoids, terpenoids, and other phytochemicals that can act as reducing agents or stabilizers in the synthesis process.[12] Overall, the presence of flavonoids, polysaccharides, phenolics, and other secondary metabolites with redox capacity in plants contributes to their antioxidant, anti-inflammatory, and protective properties, both for the plants themselves and for potential applications in various industries.[13,14].In this study the use of green tea extract in the synthesis of Fe-Nanoparticles offers several advantages.It eliminates the need for hazardous reducing agents or stabilizers, thereby reducing the environmental impact of the synthesis process.Additionally, the polyphenols from green tea extract may introduce unique properties or functionalities to the Fe-Nanoparticles, potentially leading to enhanced performance or novel applications [15,16].These components are biodegradable, non-toxic and are alternative synthesis of chemicals [17][18][19].Although in present study photo-catalytic activity of Fe -Nanoparticles was examined for MG dye, almost 71% of dye was degraded within 150 min, which proves its excellent photo-catalytic efficiency.

Synthesis of metal nanoparticles
Green tea leaves were purchased from the local market and were used for the preparation of iron (Fe) nanoparticles similar method was adopt by Huang, Weng, Chen, Megharaj and Naidu [20].

Preparation of green leaves extract
Green tea leaves were purchased from market.Extract of green tea leaves was added to the FeCl3 solution for synthesis of Iron nanoparticles.50 g green tea leaves was taken to prepare extract.500 ml of De ionized water was taken in 1000 ml of conical flask and 50 g of leave extract was added.Flask containing this mixture was heated at 80 0 C for 20 min as shown in Fig. 1.After that mixture was filtered at room temperature.This solution can be used up to one week keeping it at 5 0 C.

Synthesis of Fe-Nanoparticles
Green tea leaves extract was substituted in FeCl3 solution for preparation of Fe-Nanoparticles.Take 16.22 g of FeCl3 granulate in 1000 ml of D.I. water.FeCl3 solution and solution obtained after filtration of tea leaves extract should be mixed in ratio 1:1.Mechanical stirrer at room temperature is used to stirrer the prepared mixture.The arrival of black precipitates reveals the reduction of Fe +2 ions.These precipitates were centrifuged to the rpm of 15,000 for 15 min.Finally, collected Fe nanoparticles were dried in oven at 65 0 C for 3hr.

PHOTOCATALYTIC ACTIVITIES
In this experiment, 10 mg of Methylene blue (MB) was diluted in 1 L D.I. water for preparation of stock solution.10 mg Fe nanoparticles were used as catalyst in 250 ml of stock solution.Prior to irradation under sunlight , solution was magnetically stirred in dark place for 30 min to achieve an adsorptiondesorption stability.The stock solution containg catalyst was irradiated under sunlight for 120 min.After every 15 min, 5 ml of sample solution was collected and centrifuged to remove the catalyst.The concentration of Methylene blue dye was observed by measuring the abosrption intensity at wavelength of 662 nm.

CHARACTERIZATIONS
Structural properties of synthesized Fe-Nanoparticles are determined by X-Ray diffraction (XRD).Surface morphology of the samples were analyzed using Field Emission Scanning Electron Microscopy (FESEM) by ZEISS SUPERA 55, The size is decreased from 20 μm to 200 nm is depicted in Fig. 2.(a) and (b).The prepared nanoparticles are in range of 200 nm.The photo catalytic absorption was examined by employing The Shimadzu UV 3600 spectrophotometer.The magnification which was used for the study of particle size for green tea nanoparticles is 50.00KX.PANalytical X'Pert PRO powder x-ray diffractometer in scan rate of 10° to 80° at room temperature is used to perform powder x-ray diffraction pattern.X-ray diffraction (XRD) is based on the dual wave particle nature of x-rays to reveal the information about the structure of crystalline materials'-ray diffraction structures of Fe-nanoparticles is determined and scanned at 2θ position.The peaks at 2θ values of green tea nanoparticles are 22.31 0 , and 30.52 0 are shown in the Fig. 3. XRD results are similar to Tejaswi Mareedu et al [21]

RESULTS AND DISCUSSION
By using green leaves tree extract as reducing agent, we have synthesized the Iron nano particles in smooth and feasible way.Green tea balances an extra quantity of polyphenols and other organic components which are present in it.It has been discovered that almost 33% part contains polyphenols which helps in reducing the salt antecedent to nanoparticles.Reduction technique is carried out in two steps: 1) in primary method, antecedent is added to form a compound by breaking the OH bond so that partial bond can be formed with metal iron.2) Secondly the partial bond breaks and electron is transmitted to decrease the metal ions to nano particles.This leads them to oxidize to form ortho-quinone.

Photocatalytic degradation of MB dye
The essential purpose of this research work is to degrade the organic pollutant.In our study Methylene Blue (MB) dye is used as model organic pollutants.The Fe-nanoparticles are used as photo-catalyst to test the degradation of MB dye.The necessary amount of catalyst was amalgamated in stock solution of dye and was irradiated under direct sunlight for different time breaks under continuous stirring.The irradiated samples were centrifuged, filtered and then UV-vis spectrophotometer was used to determine the absorbance spectra.The degradation results of MB dye are shown in Fig. 4. The MB absorbance spectrum was reduced with time; moreover change of color from light blue to light green and then becoming colorless gives information regarding degradation of dye.The degradation efficiency of the catalyst was calculated by 71% efficiency is shown by Fe-nanoparticles for degradation of MB dye .When the light energy is in comparison or more than the band gap, the electrons attain energy and shifts from Valence band (VB) to the conduction band (CB) which induces holes (h + ) in the VB and electron (e -) in CB.These holes counter with the molecules of water and OH radicals are produced, which further oxidized the organic pollutant.
Electrons from conduction band react with oxygen in the reduction process and induce OH radicals.These radicals decrease the organic pollutant.This oxidation and reduction process degrades the organic pollutant under sunlight.

CONCULSION
Green tea leaves extract was used for preparation of Fe-nanoparticles.This is natural and less expensive process to synthesis Iron NPs, further this can enhance the industrial production of metal nanoparticles without using harmful agents.From results we conclude that Fe-NPs exhibits efficient photo-catalytic activity.Applications and future research: Once the Fe-nanoparticles are successfully prepared, they can be investigated for various applications in fields such as catalysis, biomedicine, environmental remediation, and energy storage.The unique properties of nanoparticles at the Nano scale make them attractive for a wide range of research areas.It can be concluded that Fe-NPs synthesis through green tea leaves are sustainable and environmental friendly.

Figure 4 .
Figure 4. Photo-catalytic absorption spectra of Fe-nanoparticles under sunlight