Abstract

SYNTHESIS, CHARACTERIZATION, CATALYTIC BIODEGRADATION, ANTIBACTERIAL ACTIVITY AND THERMAL PROPERTIES OF RED CUPROUS OXIDE NANOPARTICLES

Khwaja Salahuddin Siddiqi*, Mohammad Rashid, Aziz ur Rahman, Mohammad Shoeb, Shahid Husain and Sumbul Rehman

ABSTRACT

Cuprous oxide nanoparticles (Cu2O NPs) were synthesized from cupric sulfate and dextrose in an alkaline medium and characterized by UV-Vis, FTIR, Raman spectroscopy, XRD, SEM, TEM, EDX, and DLS techniques. The nanoparticles have an average hydrodynamic radius range of 77.4 to 387.8 nm, with specific particles at 171 ± 27.16 nm fully dispersed in water and a polydispersity index of 0.445, indicating high quality. These crystalline nanoparticles exhibit spherical, square, pentagonal, and hexagonal shapes. XRD analysis shows a cubic cuprite structure with an average size of 24.81 nm. Remarkably, they remain stable for months in the atmosphere despite the tendency to oxidize to black cupric oxide. In photocatalytic tests, methylene blue (MB) degradation with ascorbic acid as a catalyst resulted in a 97.7% reduction. The reduced form of colourless methylene blue was re-oxidised slowly, which was confirmed by the restoration of its blue colour. The nanoparticles showed significant antibacterial activity against six gram-positive and four gram-negative bacterial strains. It was observed that the Cu2O NPs were more effective in the growth inhibition of some pathogenic bacteria than the antibiotic ciprofloxacin. Their differential thermal analysis showed that the NPs were stable in the 303-1173 0K range.

Keywords: Cuprous oxide Nanoparticles, Catalysis, Methylene blue, Antibacterial, Thermal stability.