S. Narayana Vavilapalli
Department of Chemistry, Andhra University, 530003, Visakhapatnam, Andhra Pradesh, India. & Government Degree College, 535002, Vizianagaram Town, Andhra Pradesh, India.

Santi Shobha Rani
Regional Joint Director of Collegiate Education, Zone 1&2, 533101, Rajamahendravaram, Andhra Pradesh, India.

Gopi Mamidi
Department of Chemistry, Dr. V. S. Krishna Government Degree College, Visakhapatnam, Andhra Pradesh, India.

Sathish Mohan Botsa
Bio Enviro Chemical Solutions, 530017, Visakhapatnam, Andhra Pradesh, India.

DOI https://doi.org/10.33889/PMSL.2026.5.2.017

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Abstract

Water pollution caused by 4-nitrophenol (4-NP) and antibiotic-resistant pathogens presents a significant challenge for sustainable wastewater treatment. In this study, nickel oxide nanoparticles (NiO NPs) were synthesized via a green route using Ixora chinensis leaf extract and evaluated for their dual catalytic and antimicrobial performance. Structural characterization revealed crystalline NiO with an average crystallite size of 19.8 nm (XRD, Scherrer equation) and particle sizes ranging from 15-25 nm (TEM). The nanoparticles exhibited a mesoporous structure with a BET surface area of 24.6 m2/g and a Type IV adsorption isotherm, indicating enhanced surface reactivity. The biosynthesized NiO NPs demonstrated excellent catalytic efficiency, achieving >98% reduction of 4-NP to 4-aminophenol within 35 minutes, following pseudo-first-order kinetics (k = 0.079 min-1, R² = 0.987). Notably, the catalyst retained over 80% of its activity after 10 successive cycles, confirming excellent stability and reusability. In parallel, the nanoparticles exhibited dose-dependent antibacterial activity, with inhibition zones of 8-10 mm at 100 µg/mL against both Gram-negative (E.coli) and Gram-positive (S.aureus) strains, comparable to standard amoxicillin control. The enhanced performance is attributed to phytochemical capping agents from Ixora chinensis, which facilitate active surface sites and promote reactive oxygen species generation for microbial inactivation. These results demonstrate a sustainable nanomaterial for simultaneous pollutant degradation and pathogen control in water treatment.

Keywords- Ixora chinesis, NiO nanoparticles, Reduction of nitrophenol, Antimicrobial activity.

Citation

Vavilapalli, S. N., Rani, S. S., Mamidi, G., & Botsa, S. M. (2026). Ixora Chinesis Leaf Extract Mediated Mesoporous NiO Nanoparticles for Simultaneous Catalytic Reduction of 4-Nitrophenol and Antimicrobial Resistance. Prabha Materials Science Letters, (2), 308-322. https://doi.org/10.33889/PMSL.2026.5.2.017.