Green Synthesis of Bi2MoO6 NPs using Euphorbia Leaf Extracts for Removal of Toxic Organic Pollutant, Antibacterial and Antioxidant Performance

Abstract

The investigation of instantaneous removal of multiple organic pollutants from using nanomaterials flags an innovative opportunity that is permitted from subordinate pollution and economical. In the aquatic atmosphere, river water contains large amount of organic effluent releases from the textile industries, which can stimulus the process of adsorption hence, the removal of toxic organic pollutant from the water bodies becomes a true challenge. Owing to this, we try to synthesize of Bi2MoO6 NPs using Euphorbia leaf extracts as green reducing and capping agents, leaf extracts play a dual role to reduce both bismuth and molybdenum into corresponding metal oxide. As synthesized material were characterized various spectroscopic and microscopic techniques for the structural and morphological authentication. X-ray diffraction (XRD) confirmed the orthorhombic phase with crystalline size 10-12 nm. Elemental composition and purity of the NPs (Bi, Mo, C, and O elements) were confirmed via energy-dispersive X-ray spectroscopy (EDS). UV-DRS exposes band gap about 2.44 eV, which exhibited excellent semiconducting property for the removal of toxic compound. Surface area and pore size were assessed by Brunauer–Emmett–Teller (BET) analysis, obtained surface area found to be 82. 66 m2/g and pore size was 9.9 nm. Morphological studies and particle size distribution were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), TEM revealed nearly spherical NPs with average particle size 30-35 nm. However, the adsorption studies revealed that Bi2MoO6 NPs exhibit an outstanding removal e?ciency for different dyes found to be 60.3, 79.5 and 66.8 mg g?¹ for Erichrome black T (EBT), Malachite green (MG) and Eosin yellow (EY) respectively. However, the kinetic studies follows pseudo-second order kinetics, and the equilibrium data authenticate for Freundlich and Langmuir isotherm. Furthermore, Bi2MoO6 NPs showed excellent activity against E. coli, S. aureus followed by B. subtilis and K. pneumoniae. DPPH scavenging activity, in methanolic solvent showed higher radical inhibition than ethanolic solvent.

Introduction

This study addresses the growing problem of water pollution, particularly contamination caused by industrial organic dyes, heavy metals, pesticides, and pharmaceutical residues. Traditional wastewater treatment methods such as adsorption, coagulation, and photodegradation are commonly used, but they face limitations. Although nanomaterials offer high efficiency, many are difficult to separate, recover, and may pose environmental risks.

To overcome these challenges, the study develops a green synthesis approach for preparing bismuth molybdate (Bi?MoO?) nanoparticles using Euphorbia leaf extract as a natural reducing and stabilizing agent. This eco-friendly method avoids toxic chemicals and high energy consumption associated with conventional synthesis techniques. The synthesized nanoparticles were characterized using techniques such as XRD, FTIR, SEM, TEM, EDX, UV–DRS, and BET analysis, confirming their crystalline, nanoscale, and phase-pure structure.

The prepared Bi?MoO? nanoparticles were tested for:

• Dye removal (adsorption studies) using EBT, Methylene Green, and Eosin Yellow.

  • Maximum adsorption capacities were 60.3, 79.5, and 66.8 mg/g, respectively.

  • Adsorption followed pseudo-second-order kinetics and fit both Langmuir and Freundlich isotherm models.

• Antibacterial activity against E. coli, S. aureus, K. pneumoniae, and B. subtilis, showing effective inhibition.

• Antioxidant activity using the DPPH assay, with stronger radical scavenging in methanol than ethanol.

Overall, the study demonstrates that plant-mediated green-synthesized Bi?MoO? nanoparticles are effective, eco-friendly materials for wastewater treatment, antimicrobial applications, and antioxidant activity, making them promising for environmental remediation.

Conclusion

In conclusion, the existing work fruitfully exposed the green synthesis of Bi2MoO6 NPs using Euphorbia leaf extract, which performed a dual role as both the reducing and capping agent. As synthesized material were authenticate for their structural and morphological explorations techniques recognised the operative formation of the NPs. The TEM analysis exposed that of Bi2MoO6 NPs having a size of nearly 30-35 nm. The result explored a single-phase orthorhombic phase. Furthermore, the NPs exhibited a large surface area of 82. 66 m2/g, confirming their mesoporous nature. The Bi2MoO6 adsorbent revealed a remarkable removal efficiency for MG, EY and EBT even at small doses, under environmentally conditions. The mechanistic methodology of adsorption kinetically scrutinized the pseudo-second-order kinetic model, while the equilibrium data were fitted for both Langmuir and Freundlich isotherms reinforced the surface interaction mechanisms between the NPs and organic toxic dyes. The maximum removal e?ciency was found to be 60.3, 79.5 and 66.8 mg g?¹ for EBT, MG and EY dyes respectively. Moreover, Bi2MoO6 NPs showed exceptional activity at a concentration of 0.1mg/100µL against E. coli (23 mm), S. aureus (22 mm) followed by K. pneumonia (17 mm) and B. subtilis (13 mm). The DPPH scavenging activity, in methanolic solvent showed higher radical inhibition activity than ethanolic solvent. The compared result with standard ascorbic acid in all concentration of assay, Euphorbia extract, Bi2MoO6 NPs showed maximum inhibition at a concentration of 500 ?g/mL in both solvents. In Complete, synthesized Bi2MoO6 NPs offer an encouraging, workable solution for an effective elimination of toxic heavy metal ions from the aqua sphere as well as good sustainability against microbial pathogens.

References

[1] K. Y. Kumar, H. B. Muralidhara, Y. A. Nayaka, J. Balasubramanyam, and H. Hanumanthappa, “Low-cost synthesis of metal oxide nanoparticles and their application in adsorption of commercial dye and heavy metal ion in aqueous solution,” Powder Technol, vol. 246, pp. 125–136, Sep. 2013, doi: 10.1016/j.powtec.2013.05.017. [2] R. Sarathi et al., “5 Journal of Chemical Reviews Photocatalytic Degradation of Malachite Green Dye by Metal Oxide Nanoparticles-Mini Review Photocatalytic Degradation of Malachite Green Dye by Metal Oxide Nanoparticles-Mini Review,” J. Chem. Rev, vol. 5, no. 1, 2023, doi: 10.22034/JCR.2023. [3] A. A. Sabrin A, “Textile Dye Removal from Wastewater Effluents Using Chitosan-ZnO Nanocomposite,” J Text Sci Eng, vol. 05, no. 03, 2015, doi: 10.4172/2165-8064.1000200. [4] D. Nayeri and S. A. Mousavi, “Dye removal from water and wastewater by nanosized metal oxides - modified activated carbon: a review on recent researches,” Journal of Environmental Health Science and Engineering, vol. 18, no. 2. Springer Science and Business Media Deutschland GmbH, pp. 1671–1689, Dec. 01, 2020. doi: 10.1007/s40201-020-00566-w. [5] W. S. Al-Arjan, “Zinc Oxide Nanoparticles and Their Application in Adsorption of Toxic Dye from Aqueous Solution,” Polymers (Basel), vol. 14, no. 15, Aug. 2022, doi: 10.3390/polym14153086. [6] A. A. Alanazi, “Investigation of malachite green removal using graphene oxide-zinc oxide composite from aqueous solution: synthesis, characterization and application,” Desalination Water Treat, vol. 293, pp. 243–252, May 2023, doi: 10.5004/dwt.2023.29519. [7] S. Modi et al., “Recent and Emerging Trends in Remediation of Methylene Blue Dye from Wastewater by Using Zinc Oxide Nanoparticles,” Water (Switzerland), vol. 14, no. 11. MDPI, Jun. 01, 2022. doi: 10.3390/w14111749. [8] P. Saravanan, R. Gopalan, and V. Chandrasekaran, “Synthesis and Characterisation of Nanomaterials,” 2008. [9] V. Srivastava, D. Gusain, and Y. C. Sharma, “Synthesis, characterization and application of zinc oxide nanoparticles (n-ZnO),” Ceram Int, vol. 39, no. 8, pp. 9803–9808, Dec. 2013, doi: 10.1016/j.ceramint.2013.04.110. [10] V. M. Muinde, J. M. Onyari, B. Wamalwa, and J. N. Wabomba, “Adsorption of malachite green dye from aqueous solutions using mesoporous chitosan–zinc oxide composite material,” Environmental Chemistry and Ecotoxicology, vol. 2, pp. 115–125, Jan. 2020, doi: 10.1016/j.enceco.2020.07.005. [11] T. M. Tamer et al., “Formation of zinc oxide nanoparticles using alginate as a template for purification of wastewater,” Environ Nanotechnol Monit Manag, vol. 10, pp. 112–121, Dec. 2018, doi: 10.1016/j.enmm.2018.04.006. [12] Z. Monsef Khoshhesab and S. Souhani, “Adsorptive removal of reactive dyes from aqueous solutions using zinc oxide nanoparticles,” Journal of the Chinese Chemical Society, vol. 65, no. 12, pp. 1482–1490, Dec. 2018, doi: 10.1002/jccs.201700477. [13] R. Saravanan, V. K. Gupta, T. Prakash, V. Narayanan, and A. Stephen, “Synthesis, characterization and photocatalytic activity of novel Hg doped ZnO nanorods prepared by thermal decomposition method,” J Mol Liq, vol. 178, pp. 88–93, Feb. 2013, doi: 10.1016/j.molliq.2012.11.012. [14] R. Saravanan et al., “ZnO/Ag nanocomposite: An efficient catalyst for degradation studies of textile effluents under visible light,” Materials Science and Engineering C, vol. 33, no. 4, pp. 2235–2244, May 2013, doi: 10.1016/j.msec.2013.01.046. [15] R. Saravanan et al., “ZnO/Ag/CdO nanocomposite for visible light-induced photocatalytic degradation of industrial textile effluents,” J Colloid Interface Sci, vol. 452, pp. 126–133, Aug. 2015, doi: 10.1016/j.jcis.2015.04.035. [16] R. Saravanan, V. K. Gupta, V. Narayanan, and A. Stephen, “Comparative study on photocatalytic activity of ZnO prepared by different methods,” J Mol Liq, vol. 181, pp. 133–141, May 2013, doi: 10.1016/j.molliq.2013.02.023 [17] M. Ghaedi, F. N. Azad, K. Dashtian, S. Hajati, A. Goudarzi, and M. Soylak, “Central composite design and genetic algorithm applied for the optimization of ultrasonic-assisted removal of malachite green by ZnO Nanorod-loaded activated carbon,” Spectrochim Acta A Mol Biomol Spectrosc, vol. 167, pp. 157–164, Oct. 2016, doi: 10.1016/j.saa.2016.05.025. [18] J. N. Hasnidawani, H. N. Azlina, H. Norita, N. N. Bonnia, S. Ratim, and E. S. Ali, “Synthesis of ZnO Nanostructures Using Sol-Gel Method,” Procedia Chem, vol. 19, pp. 211–216, 2016, doi: 10.1016/j.proche.2016.03.095. [19] Madhusudan P, Yu J, Wang W, Cheng B, Liu G (2012) Facile synthesis of novel hierarchical graphene–Bi2O2CO3 composites with enhanced photocatalytic performance under visible light. Dalton Trans 41(47):14345–14353. [20] Meng X, Zhang Z (2017) Bi2MoO6 co-modified by reduced graphene oxide and palladium (Pd2+ and Pd0) with enhanced photocatalytic decomposition of phenol. Appl Catal B 209:383–393. [21] Miao Y, Pan G, Huo Y, Li H (2013) Aerosol-spraying preparation of Bi2MoO6: a visible photocatalyst in hollow microspheres with a porous outer shell and enhanced activity. Dyes Pigm 99(2):382–389. [22] Nakata K, Fujishima A (2012) TiO2 photocatalysis: design and applications. J Photochem Photobiol, C 13(3):169–189 [23] Iriarte-Velasco U, Chimeno-Alanis N, Gonzalez-Marcos M P, et al. Relationship between Thermodynamic Data and Adsorption/Desorption Performance of Acid and Basic Dyes onto Activated Carbons[J]. Chemical & Engineering Data, 201 American Journal of Sciences and Engineering Research www.iarjournals.com 20 www.iarjournals.com [24] Acar E T, Ortaboy S, Atun G, et al. Adsorptive removal of thiazine dyes from aqueous solutions by oil shale and its oil processing residues: Characterization, equilibrium, kinetics and modeling studies[J]. Chemical Engineering Journal, 2015, 276: 340-348. [25] Bai S, Shen X, Zhong X, et al. One-pot solvothermal preparation of magnetic reduced graphene oxide-ferrite hybrids for organic dye removal[J]. Carbon, 2012, 50: 2337-2346. [26] Chen M, Huang Y, Chu W. et al. Exploring a broadened operating pH range for norfloxacin removal via simulated solar-light-mediated Bi2WO6 process[J]. Chinese Journal of Catalysis, 2019, 40: 673-680. [27] Yu C, He H, Liu X, et al. Novel SiO2 nanoparticle-decorated BiOCl nanosheets exhibiting high photocatalytic performances for the removal of organic pollutants[J]. Chinese Journal of Catalysis, 2019, 40: 1212-1221. [28] Yang K, Li X, Zeng D, et al. Review on heterophase/homophase junctions for efficient photocatalysis: The case of phase transition construction[J]. Chinese Journal of Catalysis, 2019, 40: 796-818. [29] Yu C, He H, Zhou W, et al. Novel rugby-ball-like Zn-3(PO4) (2) @C3N4 photocatalyst with highly enhanced visible-light photocatalytic performance[J]. Separation and Purification Technology, 2019, 217: 137-146. [30] Hu J, Chen D, He J, et al. Recyclable Carbon Nanofibers@Hierarchical I-Doped Bi2O2CO3-MoS2 Membranes for Highly Efficient Water Remediation under Visible-Light Irradiation [J]. ACS Sustainable Chemistry & Engineering, 2018, 6: 2676-2683. [31] Rahmani M, Sasani M. Evaluation of 3A zeolite as an adsorbent for the decolorization of rhodamine B dye in contaminated waters[J]. Applied Chemistry, 2016, 41: 83-90. [32] Hegazi H. Removal of heavy metals from wastewater using agricultural and industrial wastes as adsorbents[J]. HBRC, 2013, 93: 276-282. [33] Javaid A, Bajwa R, Shafique U, et al. Removal of heavy metals by adsorption on Pleurotus ostreatus[J].Biomass & Bioenergy, 2011, 35: 1675-1682. [34] Mondal S. Methods of dye removal from dye house effluent-An overview[J]. Environmental Engineering Science, 2008, 25: 383-396. [35] Salleh M A M, Mahmoud D K, Karim W A W A, et al. Cationic and anionic dye adsorption by agricultural solid wastes: A comprehensive review[J]. Desalination, 2011, 280: 1-13. [36] Alizadeh R, Kazemi R K, Rezaei M R, et al. Ultrafast removal of heavy metals by tin oxide nanowires as new adsorbents in solid-phase extraction technique[J]. International Journal of Environmental Science and Technology, 2018, 15: 1641-1648. [37] Hu H, Srinivasan P. Mesoporous high-surface-area activated carbon[J]. Microporous and Mesoporous Materials, 2001, 43: 267-275 [38] Selvam P, Preethi S, Basakaralingam P, et al. Removal of rhodamine B from aqueous solution by adsorption onto sodium montmorillonite[J]. Hazardous Materials, 2008, 155: 39-44. [39] R. Sivaraj, Pattanathu K.S.M. Rahman, P. Rajiv, Hasna Abdul Salam, R. Venckatesh Biogenic copper oxide nanoparticles synthesis using Tabernaemontana divaricate leaf extract and its antibacterial activity against urinary tract pathogen, Spectrochim. Acta A Mol. Biomol. Spectrosc., 133 (2014), pp. 178-181 [40] N.Z. Shah, N. Muhammad, S. Azeem, A. Rauf, Studies on the chemical constituents and antioxidant profile of Conyza Canadensis, Midd-East J. Med. Plants Res., 1 (2012), pp. 32-35

Copyright

Copyright © 2026 Prashant P. Mungle, Priyadarshani N. Deshmukh, Pravin K. Gaidhane. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.