Silver nanoparticles (AgNPs) are widely recognized as a prominent antimicrobial agent and have found applications in the field of medicine. This study focuses on the synthesis of AgNPs utilizing the natural reducing agent of Ceylon olive (Elaeocarpus serratus), presenting an economically viable and ecologically friendly approach. For the first time, this research demonstrated the synthesis of AgNPs using phytochemicals extracted from Ceylon olive, serving as both natural reducing and stabilizing agents. The synthesized AgNPs were characterized with UV–visible spectroscopy, a particle size analyzer (PSA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray spectrometer (EDX). The UV–visible spectra primarily indicated the formation of the AgNPs by the surface plasmon resonance band around 434 nm. SEM analysis confirmed the presence of silver nanoparticles within a size range of 50–110 nm, with an average size of approximately 70 nm. FTIR determined that proteins, phenols, and flavonoids may have acted as reducing and capping agents. Experimental parameters were optimized to improve the yield and size of the AgNPs and eventually evaluate their antibacterial properties. The well diffusion method exhibits a significantly larger zone of inhibition for Gram-negative bacterial strains (18.4 ± 0.55 mm for Pseudomonas aeruginosa and 14.4 ± 0.55 mm for Escherichia coli) compared to Gram-positive bacterial strains (11.6 ± 0.55 mm for Staphylococcus aureus and 10.4 ± 0.55 mm for Staphylococcus epidermidis) for 50 µg/mL AgNPs. These findings demonstrate that AgNPs synthesized with Ceylon olive have the potential to develop into novel materials for bacterial-mediated diseases.

Antimicrobial resistance is a growing global health threat, motivating the design of materials with enhanced, broad-spectrum antimicrobial performance under practical conditions. Zinc oxide (ZnO) nanoparticles are attractive for their intrinsic antimicrobial activity, but their photocatalytic efficacy is typically limited to UV irradiation due to a wide band gap. Here, Cu-doped ZnO (Cu_xZn_100−xO) nanohybrids were synthesized via co-precipitation with varying Cu contents (x = 0, 3, 5, 7, 10) and calcination temperatures (450 °C and 650 °C) to enable visible-light activation and synergistic antimicrobial activity. XRD, FTIR, SEM-EDX, UV-vis DRS, and AAS analyses confirmed the successful incorporation of Cu, along with corresponding changes in morphology and band gap modulation. The 7% Cu-doped ZnO prepared at 450 °C exhibited the lowest band gap and the highest photocatalytic activity toward methylene blue under visible light, alongside the strongest antioxidant capacity (IC₅₀ = 151 μg mL⁻¹). Antimicrobial activity assessed by agar well diffusion demonstrated superior inhibition zones for 7% Cu–ZnO compared to pure ZnO across gram-positive (Staphylococcus aureus, MRSA), gram-negative (Escherichia coli, Salmonella typhi, Shigella sonnei), and fungal (Candida albicans) strains. Cu doping markedly enhanced the antimicrobial performance of ZnO nanofiber mats. The 7% Cu–ZnO mats exhibited significantly larger inhibition zones against both Gram-positive and Gram-negative bacteria as well as C. albicans compared to pure ZnO mats, confirming their superior broad-spectrum activity. 7% Cu-doped ZnO processed at 450 °C functions as a visible-light-active, broad-spectrum antimicrobial nanohybrid, and its incorporation into cellulose acetate nanofibers provides a cost-effective, scalable membrane platform for advanced antimicrobial and photocatalytic applications.

Fabrication of Cu2O quantum dots (QDs) sensitized p-CuSCN photoelectrode provides a significant photocurrent enhancement in photoelectrochemical medium for the first time. The variation of photocurrent quantum efficiency (Ф%) with Cu2O amount formed on p-CuSCN was presented. Here, two maxima of photocurrent could be observed in Cu/p-CuSCN/Cu2O photoelectrodes. The first photocurrent peak was due to the Cu2O QDs sensitization on p-CuSCN layer, and the second photocurrent peak was due to the formation of p-n junction. Time development of the photocurrent for Cu/p-CuSCN/n-Cu2O photoelectrodes and material characterization from Fourier Transform Infrared (FTIR) spectra, Scanning Electron Microscope (SEM) images, Energy Dispersive X-ray Spectroscopy (EDX) and X-ray diffraction (XRD) were done in this study in detailed.

The manufacture of composite materials reinforced with bristle fiber that possess distinct properties is highly attractive for novel applications. The quality variations in coir fiber-reinforced rubber composites (CFRC) are mainly affected by several factors, including the type of rubber matrix used, the interfacial adhesion between the coir fiber and the rubber matrix, the fiber length, and fiber loading. The objectives of this study were to assess and characterise coir fibers extracted from diverse Sri Lankan coconut varieties to identify high-quality coir fiber suitable for the fabrication of high-performance coir fiber-reinforced rubber composites, and the optimal range of coir fiber length and loading was investigated to maximize the mechanical properties of the composites. In this research, the extracted bristle fiber from different coconut varieties was examined for distinct properties and chemical composition. The varying lengths, specifically ranging from 0 to 0.5 mm and 0.5-1.0 mm of fiber from selected coconut varieties, were used for making CFRC. Different loadings of the selected range of coir fiber were used for partial replacement of carbon black in CFRC. Results showed that the Kamandala and Tall x Tall varieties had significantly high tensile strengths, with the Tall x Tall variety selected due to its superior mechanical properties and high abundance. The replacement of carbon black filler in natural rubber composites with 10 phr of coir fiber obtained from the Tall x Tall variety, with a length range of 0 to 0.5 mm, possessing coir-to-carbon black weight ratios of 10/40 phr, demonstrated superior properties in terms of tensile strength, tear strength, and elongation compared to composites containing 10 phr of coir fiber with a length range of 0.5-1 mm and other coir fiber to carbon black ratios. These findings provide insightful information for the development of composite materials and promote the sustainable and responsible utilization of coconut resources.