Efficient Bioelectrochemical Cell Generation and Green Synthesis of Silver Nanoparticles Using Pomegranate and Pineapple Peel Extracts: A Comprehensive Characterization Study

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Introduction
Metal nanoparticles display distinctive optical and optoelectronic characteristics within the size range of 1-100 nm.As a result, they have been extensively utilized across diverse domains, including catalysis, electronics, optics, environmental science, and biotechnology.Tis has led to a sustained and ongoing interest in their applications [1][2][3][4].In recent years, the feld of nanotechnology has witnessed a paradigm shift towards sustainable and eco-friendly approaches for the synthesis of nanoparticles [5].
Te exploration of green synthesis methods has gained signifcant attention due to their inherent advantages over conventional chemical methods, such as reduced environmental impact, cost-efectiveness, and the use of renewable resources.One promising avenue in this context involves the utilization of plant extracts as reducing and stabilizing agents for the fabrication of nanoparticles.Among the various botanical sources, pineapple (Ananas comosus) and pomegranate (Punica granatum) peel extracts have emerged as compelling candidates for the green synthesis of silver nanoparticles (AgNPs).
One notable avenue in the realm of green synthesis involves the utilization of PgP and PnP as potent bioreducing and capping agents for the synthesis of AgNPs.PgP and PnP, often regarded as agricultural waste, have been recognized for their rich content of bioactive compounds, including polyphenols, favonoids, and enzymes [6].Tese bioactive constituents play a pivotal role in the reduction of silver ions and stabilization of the resulting nanoparticles, rendering the synthesis process not only environmentally benign but also cost-efective.
Silver nanoparticles (AgNPs) have been produced from diverse plant parts such as roots, seeds, leaves, stems, and fowers, serving various purposes, particularly in biomedical applications [7].For example, AgNPs were synthesized using aqueous extracts from plants such as Cleome viscosa, Origanum vulgare, Ocimum tenuiforum, Solanum trilobatum, Syzygium cumini, Impatiens balsamina, Lantana camara, and Centella asiatica, demonstrating antibacterial properties [7][8][9][10].Te authors in [11] utilized the root extract of Cyperus scariosus to synthesize gold nanoparticles (AuNPs) and investigated their potential applications in degrading methylene blue (MB) dye and sensing Ni 2+ in water.In previous studies, Gelidium amansii, Enteromorpha compressa, Phanerochaete chrysosporium, Bacillus brevis, and Daucus carota have also been utilized for AgNP biosynthesis, with researchers investigating their antimicrobial properties [12].Te authors in [13] researched synthesized ED-AgNPs, revealing heightened antimicrobial efcacy.Te study demonstrated greater efectiveness against Grampositive bacteria (e.g., L. monocytogenes with an inhibition zone of 18 mm) compared to Gram-negative bacteria (e.g., E. coli with an inhibition zone of 10 mm).In another investigation, the authors in [14] explored the synthesis of hydroxyethylcellulose phthalate-functionalized silver nanoparticles (HEC-PA@AgNPs) through an environmentally friendly approach, employing sunlight exposure for just a few seconds.Furthermore, the authors in [15] delved into the synthesis and characterization of adipic acid-capped silver nanoparticles (AgNPs@AA), highlighting their antimicrobial activities.Te study also investigated their application in selectively detecting Hg 2+ ions in aqueous solutions.Te green synthesis of AgNPs using PnP [16] and PgP [17] ofers several advantages, including scalability, biocompatibility, and the absence of hazardous chemicals.Te choice of these fruit peels as reducing agents is rooted in their inherent ability to facilitate the reduction of silver ions, leading to the formation of well-defned nanoparticles with controlled size and morphology.Te bioreduction process is often accompanied by additional biofunctionalization, imparting unique properties to the AgNPs that can be tailored for specifc applications [18].Te authors in [19] researched synthesizing silver nanoparticles (AgNPs) by utilizing a polar extract obtained from Cotoneaster nummularius leaves.Furthermore, the authors in [20] presented a groundbreaking method involving the application of olive fruit extract for the green synthesis of AgNPs, achieved through sunlight irradiation lasting only tens of seconds.Numerous in vitro experiments have illustrated the substantial antimicrobial capabilities of silver nanoparticles (AgNPs).Some of these investigations have underscored their potential to overcome resistance exhibited by certain bacterial strains [21,22].In addition, AgNPs have been found to play a role in anticancer therapy by inducing apoptosis and facilitating the targeted delivery of antineoplastic agents to cancer cell sites [23].Although the precise mechanisms behind the bactericidal and cytotoxic efects remain unclear, there is sufcient compelling evidence in the literature to indicate that the method of synthesis and the reducing agents employed in their synthesis signifcantly contribute to determining the level of toxicity and antimicrobial efectiveness of AgNPs [24].Te authors in [25] reported the facile synthesis of silver nanoparticles via sunlight irradiation of an AgNO3 solution and 4-(phenylsulphonamido)benzoic acid (PSBA).Tis research aims to generate and characterize silver nanoparticles (AgNPs) by utilizing PgP and PnP extracts.Te production process involves controlled reduction of the initial AgNP substance, where the PgP and PnP extract serve the dual purpose of reducing and covering.Various analytical techniques, such as X-ray difraction (XRD), UV-Vis spectroscopy analysis, Raman analysis, transmission electron microscope (TEM), DLS analysis, and Raman analysis, are employed to comprehensively examine the resulting nanoparticles, assessing their size, arrangement, composition, and durability.
In summary, this study highlights the impressive efcacy of Ag nanoparticles utilizing PgP and PnP extracts in bioelectrolyte power generation systems, presenting a straightforward, cost-efective, and environmentally friendly approach for AgNPs synthesis.Tus, the potential of AgNPs for PgP and PnP to provide a novel foundation for the development of bioelectrochemical cells is underscored, emphasizing the need to explore their impact on these cells.

Techniques and the Systematic Approach
2.1.Substances and Components.Silver nitrate was acquired from Confdence Scientifc CO.Ltd, Hatkhola road, Bangladesh.Pomegranate (Punica granatum) fruits and pineapple (Ananas comosus) fruits were sourced from a local supermarket in Uttara, Dhaka, Bangladesh.All solutions were prepared using distilled water, and glassware was meticulously cleaned with distilled water and oven-dried before usage.

Te Generation of Extracts.
To minimize dust contamination, the PgP underwent a thorough cleaning process.Tis involved reducing dust particles through separate washings of the PgP and PnP with deionized (DI) water, followed by air drying at room temperature.Subsequently, the dried PgP and PnP were individually ground into extracts using grindstones.Each extract, consisting of 50 grams of PgP and PnP, was combined with 200 milliliters of deionized water.Te mixture was then agitated on a hot plate set at 64 °C for 30 minutes using a magnetic stirrer.After cooling to room temperature, the PgP and PnP extracts were obtained by fltering the mixtures through Whatman 41 paper to remove any remaining solids.Finally, the extracts 2 Advances in Materials Science and Engineering were stored separately at 3 °C for 50 minutes.Te PgP and PnP were stored at 4 °C in the refrigerator until further use in the experiment.

Environmentally Friendly Production of Silver
Nanoparticles.To commence the trial, a 30 mL solution of AgNO 3 , having a concentration of 1.0 mM, was prepared in a 100 mL conical fask.Following this, 9 mL of extracts from PgP and PnP were delicately introduced into the solution separately.After gently agitating the mixtures, they were left to incubate in darkness for a duration of 70 minutes.Within this timeframe, a noticeable color change occurred, with the PgP transforming from orange to deep maroon and the PnP changing from light pink to red.After several days, the PgP extract solution darkened, and black sediment accumulated at the volumetric fask's bottom whereas the PnP extract solution water colored, and black sediment accumulated at the volumetric fask's bottom, confrming the successful synthesis of Ag nanoparticles. Figure 1 depicts the procedural steps for producing Ag nanoparticles from (a) PgP extract and (b) PnP extract.Figure 2 shows the color change in the solution after the addition of (a) PgP extract and (b) PnP due to the reduction of silver ions.

Te Core Concept behind a Synopsis
Cell. Cell structures were constructed by utilizing zinc and copper electrodes, and the electrolyte consisted of a solution containing fuids extracted from PgP and PnP separately.Te reaction was aided by naturally occurring silver nanoparticles, serving as catalysts with environmental origins.Te role of the copper electrode was to act as an electron collector, transferring electrons to the zinc sheet, and thereby initiating interactions with hydrogen ions and Cu 2+ ions within the system.As a result, these ions underwent a gradual transformation, leading to the production of H 2 gas and the deposition of copper atoms onto the copper electrode.Over time, the cells consistently released H 2 gas, and copper atoms progressively accumulated on the copper electrode.

Designing Nanoparticle Cell Structures.
Tree distinct organic cells were established to investigate the impact of silver nanoparticles on energy generation processes.In the initial confguration depicted in Figure 3

Functional Roles of Silver Nanoparticles in Energizing
Processes.Te active roles of Ag nanoparticle energy functions were examined in cases 1, 2, and 3, focusing on open circuit voltage and short-circuit current.Te approach adopted included assessing the energy levels of diferent cells through the formula: P � V oc × I sc .Tis same formula was applied for gauging the cells' resistance, denoted as R in � V oc /I sc .To elaborate, in this context, P signifes the cell's power.R in denotes the internal resistance of the cell.

Bioelectrochemical Cell Chemical
Reaction.Figure 4 depicts a bioelectrochemical cell.In this case, Zn serves as a sacrifcial element, acting as a cathode, while Cu serves as an anode.
Advances in Materials Science and Engineering Where Cu 2+ = reactant ion, H + = ion that reacts, and Zn 2+ = ion that reacts ion, which undergoes a reaction.

Findings and Discourse
3.1.UV-Visible Spectroscopy.Te synthesis of silver nanoparticles through the introduction of an alkali solution into the reaction mixture, accompanied by vigorous stirring, demonstrated a rapid generation of these nanoparticles.Tis process induced a noteworthy color transformation, with the PgP AgNPs transitioning from orange to maroon and the PnP AgNPs changing from light pink to colorless.Tese alterations served as visible indicators of the successful reduction of AgNO 3 , marking the formation of the desired nanoparticles [26].Te plasmon resonance of metal nanoparticles, including silver, is highly dependent on their size and shape.Smaller particles may exhibit blue shifts in their localized surface plasmon resonance (LSPR) peaks, potentially falling outside the typical range.Te specifc synthesis methods and conditions could infuence the size and shape of the nanoparticles.Figure 5 shows the UV-Vis absorption spectra showing broad surface plasmon resonance peaks of   Advances in Materials Science and Engineering (a) PgP extract (navy blue color) and PgP AgNPs (violet color) and (b) PnP extract (pink color) and PnP AgNPs (maroon color).To underscore the environmentally friendly attributes of the AgNPs, their UV absorption spectrum within the 200-600 nm range was meticulously recorded and compared with the UV spectrum of PgP and PnP.Te UV-Vis absorption spectra revealed the emergence of distinctive broad surface plasmon resonance peaks at 393 nm and 397 nm for PgP AgNPs and PnP AgNPs, respectively, by established literature data [27][28][29].Te UV-Vis absorption spectra revealed the emergence of distinctive broad surface plasmon resonance peaks at 291 nm and 297 nm for PgP and PnP extracts, respectively.Tis observation further corroborated the successful synthesis of silver nanoparticles through the chosen eco-friendly method.Noteworthy variations in absorbance values between the two extracts hinted at subtle diferences, possibly attributed to variations in particle size or shape [29].Tese nuances are crucial as they provide insights into the characteristics of the synthesized nanoparticles and contribute to the understanding of the synthesis process.Te detailed analysis of UV-Vis absorption spectra adds a layer of precision to the assessment of the synthesized AgNPs, reinforcing the credibility of the ecofriendly approach employed in their production.

XRD Analysis.
Upon mixing 9 mL of pomegranate peel (PgP) and pineapple peel (PnP) extracts individually with silver to generate silver nanoparticles (AgNPs), both the extract and the resulting nanoparticles exhibited ten peaks each in their X-ray difraction (XRD) patterns (refer to Figures 6(a .Tese values, consistent with a lattice parameter of a � 0.386 nm, align well with the face-centered cubic (FCC) silver reference from the Joint Committee of Powder Difraction Standard (JCPDS) Card no.087-0720.Te broad, discernible peaks in the XRD patterns suggest a reduction in the size of the AgNPs, indicative of high crystallinity.Additional smaller peaks imply the presence of crystalline organic compounds adsorbed on the surface of the AgNPs, a phenomenon consistent with observations in plant-based synthesis [30].Applying the Scherrer equation to the XRD pattern [31] enables the calculation of particle size by using the following formula: where D represents the mean size of crystallites (nm), K is the crystallite shape factor (approximately 0.9), λ is the X-ray wavelength, β is the full width at half maximum (FWHM) [32][33][34] in radians of the X-ray difraction peak, and θ is the Bragg angle (degrees).By utilizing this equation, the average crystal size of the silver nanoparticles produced by PgP and PnP extracts is reported as 15 nm and 47 nm, respectively.Te presence of a signifcant peak indicates the involvement of bioorganic chemicals and/or proteins throughout the nanoparticle production process.Te absence of peaks associated with impurity crystalline phases in the pattern confrms the face-centered cubic form of metallic silver.Noteworthy peaks in the XRD pattern, denoted by " * ," correspond with fndings reported in various publications [5,30,[35][36][37][38][39][40][41][42][43].
Tese peaks correspond to specifc vibrational modes associated with the constituents derived from pineapple peel extract, shedding light on the unique chemical composition and structural attributes of PnP AgNPs.In Figure 7(a), the intensive peaks are observed at 1270 cm −1 , 866 cm −1 , 740 cm −1 , and 650 cm −1 .Tese peaks indicate the interaction between the extract and AgNO3 through the carboxylic and hydrophobic groups [44,45].Te band located at 200 cm −1 , 231 cm −1 , and 312 cm −1 indicates the presence of the silver lattice vibration models [46].Te bands situated at 424 cm −1 , 468 cm −1 , 535 cm −1 , and 594 cm −1 indicate the presence of AgNPs for pomegranate peel extract.Similarly, in Figure 7(b), the intensive peaks are observed at 1272 cm −1 , 1004 cm −1 , and 860 cm −1 .Tese peaks indicate the interaction between the extract and AgNO3 through the carboxylic and hydrophobic groups [44,45].Te band located at 180 cm −1 and 318 cm −1 indicates the presence of the silver lattice vibration models [46].Te bands situated at    8(a) and 8(d), there are lots of defect sites that can be observed on the surface of the composite as well as explained nanoparticles.Te particle size distribution histogram was constructed based on the analysis of 52 nanoparticles.In Figure 8(b), the mean size of the PnP particles is 37 nm with a standard deviation of 11 nm. Figure 8(e) illustrates that the mean size of the PgP particles is 24 nm with a standard deviation of 9 nm.Furthermore, a noticeable reduction in agglomeration is observed, and smaller-sized particles are fabricated.From XRD analysis, by applying the Debye-Scherrer equation, the average crystalline size of the silver nanoparticles produced by PnP and PgP extracts is reported as 47 nm and 15 nm, respectively, which is in an agreement with the result obtained from the TEM images [47,48].Te selected area electron difraction (SAED) pattern supports this, indicating a fully crystalline structure with multiple lattice plane refections.In the SAED pattern of the AgNPs for 9 mL PnP in Figure 8(c), concentric circles are observed, indexed as (111), ( 200), (220), and (311) lattice planes, and for the synthesized AgNPs for 9 mL PgP in Figure 8(f ), concentric circles are observed, indexed as (111), ( 200), (220), and (222).Tese circles correspond well with the XRD data.Terefore, the SAED pattern indicates that synthesized AgNPs for 9 mL PnP and synthesized AgNPs for 9 mL PgP nanoparticles possess a fully crystalline structure.A comparative assessment between TEM images and XRD studies indicates that the extract signifcantly infuences nanoparticle size, playing a crucial role in controlling the size reduction process.

FTIR Study.
Te FTIR spectroscopy analysis was studied to hypothesize the possible biomolecules of PgP and PnP extracts responsible for the synthesis of AgNPs.In Figure 9(a), there is a deviation of peak observed for PgP AgNPs at 3334 cm −1 and 1626 cm −1 .It suggests that the O-H and C�O groups were adsorbed on the surface of AgNPs and involved in the reduction process.In Figure 9(c), there is a deviation of peak observed for PnP AgNPs at 3342 cm −1 and 1650 cm −1 .It suggests that the O-H and C�O groups were adsorbed on the surface of AgNPs and involved in the reduction process.Te peaks near 3324 cm −1 , 2126 cm −1 , and 1634 cm −1 (Figure 9(b)) could be due to the O-H, aliphatic C�H, and C�O stretching vibrations of favonoids/ phenolic groups.Te peak at 1224 cm −1 corresponds to the O-H bend of polyphenol and confrms the presence of an aromatic group, whereas the absorption peaks at 1132 cm −1 were assigned for C-O-C and secondary -OH groups [49] of PgP AgNPs.Te peaks near 3344 cm −1 , 2142 cm −1 , and 1634 cm −1 (Figure 9(d)) could be due to the O-H, aliphatic C�H, and C�O stretching vibrations of favonoids/phenolic groups.Te peak at 1222 cm −1 corresponds to the O-H bend of polyphenol and confrms the presence of an aromatic group, whereas the absorption peaks at 1096 cm −1 were assigned for C-O-C and secondary -OH groups [49] of PnP AgNPs.Table 1 depicts the FTIR analysis with wavenumber and functional group.
3.6.DLS Analysis.Figure 10 shows the size distribution profle of these biosynthesized silver nanoparticles of PgP and PnP AgNPs for 9 mL.Te AgNPs were found to have a size distribution ranging from 1 to 100 nm.Te DLS study is required to investigate the particle size in colloidal solution and the curve obtained by scanning the suspension of Ag nanoparticles indicates the average size (diameter) of the silver nanoparticles to be around 21 nm for PgP AgNPs and 50 nm for PnP AgNPs, which confrmed the good stability of AgNPs [49,50].

Functioning of the Summary Units for the Production of
Electrical Power.Silver nanoparticles (AgNPs) synthesized through green methods were employed in a bioelectrochemical cell to assess their impact on a power generation system.Figure 11 illustrates the infuence of AgNPs on three distinct scenarios in the bioelectrochemical cell, utilizing PgP and PnP extracts.In Figure 11

Conclusion
Silver nanoparticles (AgNPs) were successfully synthesized for the frst time using a rapid, cost-efective, and environmentally friendly approach involving pomegranate peel and pineapple peel extracts with a comparative study.Te reduction of Ag + to Ag0 was confrmed by the highest ultraviolet-visible absorbance at 360 nm for pomegranate peel and 390 nm for pineapple peel in the silver nanoparticles.Te Raman spectra of AgNPs revealed active functionalization groups crucial for their reduction.Employing biological processes led to the formation of spherical Ag nanoparticles with an average size of 15 nm for pomegranate peel and 47 nm for pineapple peel.Te TEM analysis discovered that the biologically synthesized silver nanoparticles were well dispersed with no agglomeration.Te size of nanoparticles ranges from 10 to 200 nm with diferent shapes such as spherical, triangular, hexagonal, and rod.Active functionalization groups that are crucial to the reduction of silver nanoparticles were discovered in the Raman spectra of AgNPs.While previous research has explored eco-friendly methods for producing silver nanoparticles using various plant components, this study introduced a novel aspect by investigating the impact of AgNPs on the lifespan of energy-generating organisms.Advances in Materials Science and Engineering Notably, electrochemical cells were introduced in this experiment.Te resulting AgNPs were found to enhance the longevity of pomegranate peel and pineapple peel extracts electrochemical cells in terms of energy generation.Tis discovery holds promise for characterizing and understanding the durability of electrochemical cell-mediated nanoparticle production for plant-based applications, especially in the context of prolonged use in high-quality power generators.Te fndings suggest a need for further exploration into how organic cells contribute to energy generation.
(a), zinc and copper sheets served as conductors, with identical lower sections.Te cell's electrolyte consisted of a blend of 100 ml each of PgP extract.Progressing to Figure3(b), zinc and copper plates were employed as conductors, incorporating 100 ml of PgP extract, along with 9 ml of CuSO 4 .5H 2 O individually.Moving forward to Figure3(c), the electrolyte comprised a 100 mL solution of PgP extract, exposed to 9 ml of CuSO 4 .5H 2 O, and a separate 50 ml dose of a silver nanoparticles blend.In Figure3(d), zinc and copper sheets served as conductors, with identical lower sections.Te cell's electrolyte consisted of a blend of 100 ml each of PnP extract.Progressing to Figure3(e), zinc and copper plates were employed as conductors, incorporating 100 ml of PnP extract, along with 9 ml of CuSO 4 .5H 2 O individually.Moving forward to Figure3(f ), the electrolyte comprised a 100 mL solution of PnP extract, exposed to 9 ml of CuSO 4 .5H 2 O, and a separate 50 ml dose of a silver nanoparticles blend.Figure3illustrates an experimental setup designed to evaluate the fundamental concept of cells utilizing zinc or copper components, incorporating PgP and PnP extracts, and varying concentrations of silver nanoparticles.

Figure 1 :Figure 2 :Figure 3
Figure 1: Te procedural steps for producing Ag nanoparticles from (a) PgP extract and (b) PnP extract.
20-25 minutes to properly disperse the particles in water.With dry and pure KBr crystals, FTIR studies of silver NPs manufactured by PgP and PnP extraction were carried out on the IRPrestige-21 (Kyoto, Japan) of FTIR at 4.0 cm −1 determination.

Figure 3 :
Figure 3: A testing apparatus designed to assess the fundamental concept of PgP and PnP cells utilizing zinc or copper components, (a) electrochemical cell of PgP extract, (b) electrochemical cell of PgP extract with CuSO 4 .5H 2 O solution, (c) electrochemical cell of PgP and extract with CuSO 4 .5H 2 O solution and AgNPs, (d) electrochemical cell of PnP extract, (e) electrochemical cell of PnP extract with CuSO 4 .5H 2 O solution, and (f ) electrochemical cell of PnP and extract with CuSO 4 .5H 2 O solution and AgNPs.

Figure 7 :
Figure 7: Te Raman spectra of the AgNPs of(a) PgP extract-mediated AgNPs for 9 mL and (b) PnP extract-mediated AgNPs for 9 mL.

Figure 11 :
Figure 11: Te infuence of AgNPs on three distinct scenarios in the bioelectrochemical cell, utilizing PgP and PnP extracts: (a) open-circuit voltage for PgP, (b) short-circuit current for PgP, (c) maximum power for PgP, (d) open-circuit voltage for PnP, (e) short-circuit current for PnP, and (f ) maximum power for PnP.

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Advances in Materials Science and Engineering 422 cm −1 , 529 cm −1 , 658 cm −1 , and 735 cm −1 indicate the presence of AgNPs for pineapple peel extract.Tese Raman spectroscopy's fndings not only contribute to the characterization of PgP AgNPs and PnP AgNPs but also serve as a foundation for understanding the unique vibrational and structural properties of nanoparticles synthesized from natural extracts.Te distinct spectral features provide valuable information for further research and applications in areas such as nanomedicine, catalysis, and sensor technologies.

Table 1 :
FTIR analysis with wavenumber and functional group.