Green synthesis of copper oxide nanoparticles using Ephedra Alata plant extract and a study of their antifungal, antibacterial activity and photocatalytic performance under sunlight

Abstract

In the present work, copper oxide (CuO NPs) was synthesized by an eco-friendly, simple, low-cost, and economical synthesis method using Ephedra Alata aqueous plant extract as a reducing and capping agent. The biosynthesized CuO-NPs were compared with chemically obtained CuO-NPs to investigate the effect of the preparation method on the structural, optical, morphological, antibacterial, antifungal, and photocatalytic properties under solar irradiation. The CuO NPs were characterized using X-ray diffraction (XRD), UV-VIS spectroscopy, Fourier transform infrared spectrometer (FTIR) analysis, and field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (FESEM-EDX). The photocatalytic activities of biosynthetic CuO-NPs and chemically prepared CuO-NPs were studied using methylene blue upon exposure to solar irradiation. The results showed that the biosynthesized CuO photocatalyst was more efficient than the chemically synthesized CuO-NPs for Methylene Blue (MB) degradation under solar irradiation, with MB degradation rates of 93.4% and 80.2%, respectively. In addition, antibacterial and antifungal activities were evaluated. The disk diffusion technique was used to test the biosynthesized CuO-NPs against gram-negative bacteria, Staphylococcus aureus and Bacillus subtilis, as well as C. Albicans and S. cerevisiae. The biosynthesized CuO-NPs showed efficient antibacterial and antifungal activity. The obtained results revealed that the biosynthesized CuO-NPs can play a vital role in the destruction of pathogenic bacteria, the degradation of dyes, and the activity of antifungal agents in the bioremediation of industrial and domestic waste.

Keywords: Antibacterial; Antifungal activity; Biosynthesis; CuO-NPs; Ephedra Alata; Photocatalytic.

Fig. 1

Schematic for a step-wise synthesis procedure of CuO NPs by two different routes green and chemical. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2

a) X-ray diffraction patterns of chem CuO-NPs and biosynthsized CuO-NPs.b). the shift of peak position of chem CuO-NP and biosynthesized CuO-NP.

Fig. 3

FTIR spectra of E. alata extract plant, green synthesized CuO-NPs and chemical CuO-NPs. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 4

UV–Visible spectra and optical bandgap energy of Chem CuO-NPs (a) and Biosynthesized CuO-NPs (b).

Fig. 5

FE-SEM images and EDX Spectra of synthesized CuO-NPs at different magnifications (a,b et c): chem CuO-NPs and (d,e et f): Green CuO-NPs. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 6

UV–Vis absorption spectra of photocatalytic degradation of methylene blue with respect to irradiation time (a: chem CuO-NPs and b: Green CuO-NPs). (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 7

Mechanism for degradation of MB dye by chem CuO-NPs and biosynthesized CuO-NPs.

Fig. 8

Plot of ln (C0/Ct) versus time for the degradation of MB by chem CuO-NPs (a) and biosynthesized CuO-NPs (b).

Fig. 9

The effect of the initial MB concentration on the biosynthesized CuO-NPs.

Fig. 10

pH effect on MB dye degradation using biosynthesized CuO-NPs.

Fig. 11

% Degradation rate of MB dye compared to the chem CuO-NPs and biosynthesized CuO-NPs.