
==== Front
Heliyon
Heliyon
Heliyon
2405-8440
Elsevier

S2405-8440(24)13833-9
10.1016/j.heliyon.2024.e37802
e37802
Research Article
Synthesis, characterization, and evaluation of antibacterial and antifungal activities of CuO-ZnO-Co3O4 nanocomposites
Aziz Shadha Nasser Shd.Aziz@su.edu.ye
ac⁎
Abdulwahab A.M. abduhabdulwahab@yahoo.com
b⁎⁎
Aldeen Thana Shuga a
Alqabili Dheyazan Mohammed Ali d
a Physics Department, Faculty of Science, Sana'a University, Sana'a, Yemen
b Physics Department, Faculty of Applied Science, Thamar University, Dhamar 87246, Yemen
c Al-Darb Community College, Dhamar, Yemen
d Department of public health and zoonoses, Faculty of agriculture and veterinary Thamar University, Dhamar 87246, Yemen
⁎ Corresponding author. Physics Department, Faculty of Science, Sana'a University, Sana'a, Yemen. Shd.Aziz@su.edu.ye
⁎⁎ Corresponding author. abduhabdulwahab@yahoo.com
11 9 2024
30 9 2024
11 9 2024
10 18 e3780219 3 2024
9 9 2024
10 9 2024
© 2024 The Authors. Published by Elsevier Ltd.
2024

https://creativecommons.org/licenses/by-nc/4.0/ This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).
The co-precipitation method was used to prepare CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite. The structural, morphological, and optical properties of the prepared samples were studied using X-ray diffraction (XRD), total reflection X-ray fluorescence (TXRF), transmission electron microscopy (TEM), selected area electron diffraction (SAED), diffuse reflectance spectroscopy (DRS), and zeta potential. XRD analysis revealed that the crystal structures of CuO, ZnO, and Co3O4 nanoparticles are monoclinic, hexagonal, and cubic, with average crystallite sizes of 30.8 nm, 31.8 nm, and 32.8 nm, respectively. For CuO-ZnO-Co3O4 nanocomposites, the corresponding sizes were 24.9 nm, 13.6 nm, and 16.1 nm. The optical bandgaps of CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposites were 1.5 eV, 3.14 eV, 1.2 eV, and 1.3 eV, respectively. In this study, the antibacterial activity of CuO-ZnO-Co3O4 nanocomposite against Gram-negative bacteria (E. coli, Klebsiella, pseudomonas, and Salmonella) and Gram-positive bacteria (Staphylococcus aureus) was investigated and compared with the antibiotic Azithromycin. In addition, the effect of the nanocomposite on fungi was studied and compared with the antifungal Mystatin.

Keywords

Co-precipitation
Nanocomposites
(TEM)
X-ray diffraction
Optical bandgap, antibacterial and antifungals activity
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pmc1 Introduction

Mixed metal oxide (MMO) nanocomposites are made by combining several metal oxides with nanometer-sized particles. Due to their newly discovered and significantly enhanced physicochemical and biological properties as a result of their size reduction, metal oxide nanoparticles and other nanomaterials have garnered a great deal of scientific attention recently [1]. It has some properties, including thermal, optical, electrical, photocatalytic, and structural characteristics. Nanometer-scale mixing of more than one oxide results in the formation of nanoparticles, whose properties depend on the relative concentrations of the individual oxide components in the mixture. Applications for the nanocomposites could include fuel cells, battery components, photovoltaic devices, UV detectors, gas sensors, and solar cells. Increases in carrier lifetime, charge transfer capacity, charge separation efficiency, magnetic property at room temperature, and biomedical applications may be caused by metal-oxygen and metal-metal interfaces in mixed metal oxides [[2], [3], [4], [5]]. MMO nanocomposites were prepared using common methods such as Sol- Gel [6], mechanical grinding [7], hydrothermal technique [8], Microwave-assisted [9], solid-state reaction [10], and co-precipitation method [11]. The co-precipitation method is used due to its simplicity, affordability, efficacy, room temperature growth, fast, and low cost [12].

It has been demonstrated that CuO nanoparticle cause bacterial cell membrane disruption, which results in cell death. Reactive oxygen species (ROS) and copper ions are released, resulting in oxidative stress and damage to cellular components. Furthermore, CuO nanoparticle have shown a strong antifungal effect. According to studies, they are beneficial in biological and agricultural applications because they prevent the growth of fungi such as Fusarium Oxysporum and Botrytis cinerea [13,14].

It has been discovered that ZnO nanoparticle work well against a variety of bacterial strains, including gram-positive and gram-negative bacteria. Their process includes breaking down bacterial cell membranes and producing ROS. In addition, ZnO nanoparticle work well against Aspergillus Niger and Candida albicans. They prevent spore germination and harm fungal cells structurally [[15], [16], [17], [18]].

By causing oxidative stress and rupturing bacterial cell membranes, Co3O4 nanoparticle have proven effective against a variety of bacterial strains (RSC Publishing) (Frontiers). This results in cell death. Along with though studies on Co3O4 nanoparticle are not as comprehensive as those on CuO and ZnO, research suggests that they can prevent the growth of fungi. They have demonstrated efficacy in combating pathogens such as Fusarium Oxysporum, underscoring their potential for use in biological applications [19,20].

Gram-positive and Gram-negative bacterial strains are regarded as a significant public health issue as infectious diseases become more prevalent globally. Especially with the emergence of antibiotic-resistant strains of bacteria [21]. Recently, antimicrobial resistance has increased globally, particularly for Candida infections. Most of the antifungal drugs used for treating candidiasis became resistant to most Candida species.

In this way, nanomaterials are used as antibacterial agents due to their surface, size, and structure properties. Metal oxide nanoparticles such as CuO, ZnO, and Co3O4 are excellent antibacterial agents that can be used to treat many infections caused by bacteria like Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pyrogens [[22], [23], [24], [25], [26]]. When three metal oxides are combined in a ternary system, new and improved characteristics can be produced, like stronger thermal stability, better electrical conductivity, and increased catalytic activity [27]. Previous studies have demonstrated the antibacterial properties of ternary metal oxide nanocomposites. Dias et al. have evaluated the antibacterial and antifungal activity of CuO-MgO-ZnO and CuO-Co3O4-CeO2 trioxides synthesized via precipitation [28]. Kannan et al. have described the photocatalytic and antimicrobial properties of microwave synthesized CdO-CuO-ZnO nanocomposite [29]. Antibacterial activity of the CuO-NiO-ZnO mixed metal oxide has been reported by Alam et al. [30].

As far as our knowledge is concerned, the papers on these nanocomposites are scarce and their applications have not received enough studies, so the reason for the choice and coupling of these metals. The structural, morphological, and optical properties of CuO, ZnO, and Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite were investigated. Also, antibacterial and antifungal activity were evaluated and compared between five different bacterial species and candida as a useful application of the prepared nanoparticles and nanocomposite.

2 Experimental details

2.1 Materials

Copper nitrate trihydrate (Cu(NO3)2.3H2O) (98 %) (HIMEDIA), Zinc nitrate hexahydrate (Zn (NO3)2.6H2O) (99 %) (HIMEDIA), Cobalt nitrate hexahydrate (Co (NO3)2.6H2O) (98 %) (HIMEDIA), Sodium hydroxid NaOH (98 %) (HIMEDIA), and Distilled Water (DW) were used in this work.

2.2 Preparation of CuO, ZnO, and Co3O4 nanoparticles

0.03Mof (Cu(NO3)2.3H2O) was dissolved in 100 mL of distilled water under constant stirring for 10 min. 0.1 M NaOH is added dropwise to the solution to adjust its pH value to 7, and it is stirred for 1h at ambient temperature to obtain the solution. The final solutions are kept in an airtight container overnight. The obtained precipitate is washed with distilled water several times, dried at 100 °C for 1 h, then ground using a mortar and a pestle to get a fine powder. Finally, the powder is annealed at 500 °C for 2 h to obtain the nanoparticles. These steps were repeated for other tow oxides (ZnO and Co3O4) with (Zn(NO3)2.6H2O) and (Co(NO3)2.6H2O) as starting materials (see Fig. 1).Fig. 1 Representation of the synthesis processes of CuO, ZnO,Co3O4 nanoparticals and CuO-ZnO- Co3O4 nanocomposite.

Fig. 1

2.3 Synthesis of CuO-ZnO-Co3O4 nanocomposite

To prepare (CuO-ZnO-Co3O4) nanocomposite, 0.03M of copper nitrate, zinc nitrate, and cobalt nitrate with molar ratios (1:1:1) were dissolved in 300 mL of distilled water under constant stirring for 10 min. The nanocomposite was then prepared using the same procedure as for the synthesis of CuO, ZnO, and Co3O4

2.4 Characterizations

The structural characteristics of the prepared CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite were examined using XRD (XD-2 X-ray diffractometer using CuKα (λ = 1.54 Å) at 36 kV and 20 mA, China). The concentrations of each element in the samples were measured using a TXRF (xrf, s8 tiger, German) in the Yemeni Geological Survey and Minerals Resources Board. The nanoparticle size was determined using a TEM (JEM-2100, Japan). The size of the TEM images was evaluated using ImageJ software. In the Egypt National Research Centre (DRS), Model JASCO (V-750, Japan) was used to measure the transformation of the reflectance spectra. For zeta potential and particle size, 1 mg of each sample was dispersed in 1 mL of deionized water, then sonicated for 30 min and diluted 10X with deionized water. By utilizing a particle size analyzer called Dynamic Light Scattering (DLS) (Zetasizer Nano ZN, Malvern Panalytical Ltd., United Kingdom) at a fixed angle of 173° at 25 °C, the prepared particles were examined for their particle size and size distribution in terms of the average volume diameters and polydispersity index. Each sample was examined three times. The zeta potential was calculated using the same tools.

2.5 Antibacterial and antifungal activity

2.5.1 Preparation of standardized suspension

A few colonies of similar morphology from each bacteria isolate were transferred, utilizing a sterile loop,to a tube containing 5 ml of sterile 0.85 % physiological saline. The addition of sterile saline or other colonies to the tube was applied until the turbidity was adjusted to match 0.5 McFarland standard tubes using adequate light [31].

The antibacterial effectiveness of the CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite were evaluated against five bacterial pathogens using the agar-well diffusion method. Bacterial colonies were cultured in nutrient broth at 37 °C for 24 h with gram-positive (Staphylococcus) and gram-negative (E. coli, Klebsiella, Pseudomonas, and Salmonella) organisms. 15 mL of Mueller-Hinton agar was added to Petri dishes and allowed to set up. Five different concentrations of each nanocomposite (1, 2, 4, 8, and 16) in addition to azithromycin were added as a control immediately to the plates [32]. The plates were then heated at 37 °C for 24 h of incubation. After incubation, the degree of sensitivity was determined by measuring the easily visible and clear zone of inhibition of growth produced by the diffusion of the antimicrobial agent from the wells into the surrounding medium. The diameter of the inhibition zone for each antimicrobial agent was measured and interpreted according to Poirel [33].

The only pure colony of yeast was selected using a sterile swab dipped in sterile tween 80. After being vortexed, this was suspended in 3–4 mL of sterile normal saline. A 0.5 McFarland standard was set for the suspension's turbidity. In a similar manner, the pure colony was swabbed to prepare the inoculum for mold. This suspension was then vortexed in 3–4 mL of sterile normal saline. A 0.5 McFarland standard was set for the suspension turbidity [34].

Candida was utilized to assess the antifungal activity of CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite. Petri dishes were filled with 15 mL of Sabouraud agar, which was then allowed to set. Five samples of antifungal nanocomposites (Mystatin) were then immediately added to the plates. Following that, it was left out at room temperature for 24–48 h. The size of the inhibition zone was then measured.

3 Results and discussion

3.1 X-ray diffraction (XRD)

The XRD patterns of CuO- ZnO- Co3O4 nanocomposite along with pure CuO, ZnO, and Co3O4 nanoparticles are presented in Fig. 2. The XRD pattern of CuO- ZnO- Co3O4 nanocomposite is in good agreement with standard JCPDS cards no:00-048-1548 (CuO) [35], JCPDS cards no:00-001-1136 (ZnO) [36], and JCPDS cards no: 00-042-1467 (Co3O4) [37], confirming the existence of three phases in the single matrix. The observed diffraction patterns of nanocomposite demonstrated that CuO has a monoclinic structure, ZnO has a hexagonal structure, and Co3O4 has a cubic structure. Peak positions and corresponding Miller indices for the nanoparticles and nanocomposite are listed in Table 1. There was no impurity peak noticed in the XRD pattern, confirming the successful growth of pure CuO- ZnO- Co3O4 nanocomposite.Fig. 2 XRD patterns of CuO, ZnO, Co3O4 nanoparticals and CuO–ZnO-Co3O4 nanocomposite.

Fig. 2

Table 1 The Peak positions and corresponding Miller indices for CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite.

Table 1CuO	ZnO	Co3O4	CuO-ZnO-Co3O4	
CuO	ZnO	Co3O4	
2θ	(hkl)	2θ	(hkl)	2θ	(hkl)	2θ	(hkl)	2θ	(hkl)	2θ	(hkl)	
32.26	(110)	32.1	(100)	31.04	(220)	–	–	32.3	(100)	31.46	(220)	
35.88	(11 1‾)	34.8	(200)	36.6	(311)	35.99	(11 1‾)	34.6	(002)	–	–	
38.44	(111)	36.7	(101)	38.42	(222)	38.76	(111)	36.8	(101)	39.26	(222)	
45.98	(11 2‾)	48	(102)	44.72	(400)	–	–	47.9	(102)	44.99	(400)	
49.2	(20 2‾)	57.1	(110)	59.479	(511)	49.22	(20 2‾)	56.9	(110)	59.59	(511)	
53.44	(020)	63.4	(103)	64.94	(440)	–	–	63.3	(103)	65.26	(440)	
58.74	(202)	66.2	(200)	–	–	–	–	67.04	(200)	–	–	
61.66	(11 3‾)	68.6	(112)	–	–	61.8	(11 3‾)	–	–	–	–	
66.17	(31-1)	69.7	(201)	–	–	–	–	–	–	–	–	
66.4	(310)	73.2	(400)	–	–	–	–	–	–	–	–	
68.62	(220)	–	–	–	–	68.66	(220)	–	–	–	–	
73.06	(221)	–	–	–	–	–	–	–	–	–	–	

The intensity of CuO and ZnO peaks are higher than that of Co3O4 in the CuO-ZnO-Co3O4 nanocomposite pattern (Fig. 2). This is due to the relatively lower CuO contents, as confirmed by elemental analysis. Additionally, a slight deviation of peak positions in the nanocomposite may be because of interaction between CuO, ZnO, and Co3O4 phases.

The average crystallite sizes of CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite were calculated using Debye- Scherrer's formula Eq. (1) [38,39].(1) D =(0.9 λ)/(β CoS θ)

Where λ is the wavelength of X-ray used, β is the full-width at half maximum intensity (FWHM) (in radian), θ is the diffraction angle. The lattice constant “a, b,c” determine for all prepare nanocomposite from high intense diffraction peak of (hkl) plane using the following Bragg's equation for cubic structure Eq. (2) [40](2) 1d2=[h2+k2+l2a2]

Hexagonal structure Eq.3 [41].(3) 1d2=43[h2+hk+k2a2]+l2c2

And monoclinic structure Eq. (4) [42](4) 1d2=1sin2β[h2a2+k2sin2βb2+l2c2−2hlcosβac]

The micro-strain was determined by using Eq. (4), [42]. The calculated values of D and ε are summarized in Table 2.Table 2 The values of D and ε for CuO, ZnO, Co3O4 nanoparticles and CuO- ZnO-Co3O4 nanocomposite determined by XRD analysis.

Table 2Sample	a (A0)	b (A0)	c (A0)	D(nm)	ε	
Metal oxides	CuO	4.6	3.4	5.1	30.76	0.004058	
ZnO	3.2	–	5.1	31.79	0.0039747	
Co3O4	8.1	–	–	32.8	0.00644328	
CuO-ZnO-Co3O4
Mixed metal oxides	CuO	4.7	3.4	5.1	30.23	0.004073	
ZnO	3.23	–	5.2	26.66	0.00474	
Co3O4	8.01	–	–	26.73	0.003579	

There is a slight increase in the lattice parameters of CuO and ZnO in the nanocomposite, while that of Co3O4 decreased compared with nanoparticles. The crystallite sizes of individual CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite are shown in Table 2. The decrease in the crystallite sizes of ZnO and Co3O4 in the nanocomposite infers that CuO is the dominant phase in the nanocomposite, The result was accepted by Ishfaq et al. [43]. The decrease in crystalline size is often associated with a higher density of defects and dislocations within the crystal lattice. These defects contribute to microstrain by disrupting the regular atomic arrangement. The micro-strain (ε) of CuO and ZnO in the nanocomposite increased when compared to their values as nanoparticles. Due to the crystallite size decreased in the nanocomposite, the antibacterial and photocatalytic activity increased. This result has very good agreement with previous work [4,44].

3.2 Elemental analysis

Table 3 shows the results of the elemental composition and oxide composition of CuO-ZnO- Co3O4 nanocomposite carried out by TXRF. The results clearly indicated the existence of Cu, Zn, Co and O as elements and CuO, ZnO, Co3O4 as oxides.Table 3 TXRF analysis of CdO-CuO-Co3O4 nanocomposite.

Table 3Compound	Wt%	Elemental	Wt%	
CuO	46.83 %	Cu	37.52 %	
ZnO	30.92 %	Zn	24.67 %	
Co3O4	21.87 %	Co	16.83 %	
–	–	O	20.60 %	
P, S, Ca, Fe, Si, etc	0.38 %	P, S, Ca, Fe, Si, etc	0.38 %	

3.3 TEM analysis of CuO-ZnO-Co3O4

The size and shape of the synthesized nanoparticles and nanocomposite were characterized utilizing TEM (Fig. 3a) shows TEM images of CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite. As can be seen, CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite have spherical shapes. The image-J program was used to calculate their particle sizes, and the histogram graph was plotted in (Fig. 3b). The particle sizes of CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite are 70.7 nm, 51.8 nm, 33.4 nm, and 18.1 nm respectively. As is clear from (Fig. 3) the circular fringes in SAED patterns indicate the polycrystalline nature of the samples, and the diffraction rings matched with the XRD d-spacing of CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite. The TEM results are in good agreement with the XRD results, which showed a decrease in the crystalline size of nanocomposite compared to nanoparticles.Fig. 3 a. TEM image of CuO,ZnO,Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite. fig. 03, bparticle size distribution of CuO,ZnO,Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite. fig. 03,c.SAED crystal ring patterns obtained for the CuO,ZnO,Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite.

Fig. 3

3.4 Zeta potential and size distribution

It is essential to characterize the behavior of NPs in an aqueous state before their biological studies. The dynamic light scattering (DLS) technique is a widely used and effective method for determining the size of particles in a colloidal solution. The size of NPs is an important characteristic for the use of nanoparticles in several fields, particularly the biomedical field. Zeta potential determination is an important technique to estimate the surface charge of nanoparticles, which is helpful in the determination of the colloidal stability of NPs [30].

Nanoparticles that possess zeta potentials of more than +20 mV or less than −20 mV are considered stable colloidal suspension systems that prevents nanoparticles aggregation. On the other hand, nanoparticles with zeta potential values that fall between −30 mV and +30 mV indicate poor colloidal stability and are likely to undergo flocculation, agglomeration, or aggregation [[45], [46], [47]]. The stability behavior of synthesized CuO, ZnO,Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite have been examined using zeta potential and size distribution. As shown in Table 4 and Fig. 4.Table 4 Zeta Potential and Particle size for the CuO,ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite.

Table 4Samples	Zeta Potential (mV)	Size Distribution (nm)	
CuO	−21.7	933	
ZnO	2.78	634	
Co3O4	12	516	
CuO-ZnO-Co3O4	14.9	978	

Fig. 4 Zeta Potential Distribution the CuO,ZnO,Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite.

Fig. 4

The CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite had a mean size distribution with diameters between 500 and 980 nm. Our analysis showed that the average particle size reported by DLS was higher than the one obtained by TEM. The disparity seen between TEM and DLS aligns with many additional investigations that documented the synthesis of diverse NPs [48]. The difference in size between the nanoparticles as measured by DLS and TEM is due to the swelling of CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 in an aqueous medium. The zeta potentials of the CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite were determined to be −21.7, 2.78, 12, and 14.9 mV respectively. The CuO nanoparticles are more stable than Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite, while ZnO has poor stability. This result agrees with Ola N Hussen [49].

3.5 Optical bandgap energy

Diffuse reflectance spectroscopy was utilized to study the optical properties of CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite materials that were synthesized. Fig. 5 shows the sample's reflectance spectrum as a function of wavelength (a) in the spectral range 400–700 nm. The results demonstrate the reflectance spectrum. Utilizing the Kubelka-Munk equation, the measured reflectance was converted to absorbance [50] (see Fig. 6).(6) F(R)=(1−R)22R

Where R is the diffuse reflectance (%) and F(R) is the Kubelka-Munk function corresponding to the absorbance. The modified K-M equation was used to determine the material's bandgap energy (Eg) and the type of optical transition between the valence band (VB) and conduction band (CB) [51]:(7) (F(R)hυ)=A(E−Eg)n

Fig. 5 Diffuse reflectance spectrum (R%) of theCuO,ZnO,Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite.

Fig. 5

Fig. 6 The plot of (F(R)hν)2 vs E(eV) for direct band gap.

Fig. 6

The exponent factor n is related to the type of the optical transition and has a value of 1/2 for the direct allowed band gap, and the transition probability can be determined by the A constant. (E=hυ) is the photon energy. Plotting ((F(R)hυ)1n) versus E(eV) and extrapolating the linear portion of the plot up to (F(R)hυ)1/n = 0) can be used to estimate the Eg of materials [50]. The type of transition is determined by the best linear fit using various values of n; this kind of representation is called a Tauc model. shows the Tauc plot obtained for the as-prepared CuO, ZnO, Co3O4 nanoparticles, and CuO-ZnO-Co3O4 nanocomposite. Table 5 shows the obtained band gap Eg values of prepared samples.Table 5 Optical bandgap energy values of prepared sample.

Table 5Sample	Eg(eV)	
CuO	1.5	
ZnO	3.14	
Co3O4	1.16 &1.4	
CuO-ZnO-Co3O4	1.3	

The bandgap value of CuO- ZnO- Co3O4 nanocomposite is close to that of CuO and Co3O4 (NPs). The shift in the bandgap energy of the nanocomposite compared to the individual metal oxides may be caused by new energy states that form at the interfaces of the several metal oxides. This may cause the bandgap energy and the electrical structure to change. Co3O4 (NP) has two bandgaps at 1.4 eV and 1.16 eV; the presence of Co(III) centers in Co3O4 gives rise to a sub-band located inside the energy gap. Hence, Eg1 corresponds to the onset of O(−II)⟶Co(III) excitations, while Eg2 is the ‘‘true’’ energy gap corresponding to inter-band transitions (basic optical band gap energy, or valence to conduction band excitation) [52]. The optical band gap of CuO-ZnO- Co3O4 nanocomposite is lower than that of nanoparticles. The band gap value of nanocomposite (1.3 eV) falls within the range of a narrow band gap semiconductor. We can compare the particle size effect with the band gap only for semiconductors that have a size in the quantum dot (QD) [53,54]. Materials with such band gaps can have potential applications in fields such as photovoltaic, photocatalysis and sensors.

3.6 Antibacterial and antifungal activities

The antibacterial activity of the CuO, ZnO, Co3O4, and CuO-ZnO-Co3O4 nanocomposite was evaluated against E. coli, Klebsiella, pseudomonas, salmonella, and Staphylococcus bacterial strains by a disc different approach and is shown in (Fig. 7). The nanoparticles and nanocomposite were studied for five different concentrations: 1, 2, 4, 8, and 16 mg; these values were compared with antibacterial (Azithromycin (30 mg)).Fig. 7 Images of the CuO, ZnO, Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite inhibition zones against five types of pathogenic bacterial.

Fig. 7

Fig. 8 shows that the bacteria are sensitive to the CuO-ZnO-Co3O4 (16 mg) nanocomposite. The inhibition zones are measured as follows: 12, 15, 13, 13, and 14 mm, respectively; the weight of (8 mg) was 11, 9, 12, 9, and 12 mm respectively; and the weight of (4 mg) was 7, 9, 7, 8, and 8 mm, respectively. Its sensitivity to the ZnO (16 mg) nanoparticles was 8, 10, 13, 9, and 14 mm, respectively. The sensitivity of bacteria to azithromycin (30 mg) was 15, 18, 21, 18, and 14 mm, respectively. There is no effect of the Co3O4 and CuO nanocomposite.Fig. 8 Antibacterial activity of the CuO, ZnO, Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite and an antibiotic against five types of pathogenic bacteria.

Fig. 8

The antifungal screening was performed on candida, using Mystatin as a reference (Fig. 9). Fig. 10 shows that the candida are sensitive to the CuO-ZnO-Co3O4 nanocomposite (1, 2, 4, 8, and16 mg); the inhibition zones are measured as follows: 8, 8,9,12 and 14 mm, respectively. For CuO NPs with (1,2,4,8, and 16 mg) concentrations, the inhibition zones are measured as follows: 0,0,7,14, and 18 mm respectively, and ZnO NPs (1,2,4,8, and 16 mg) concentrations, the inhibition zones are measured as follows: 11,0,0,9, and 10 mm respectively. There is no effect on the Co3O4 NPs. The sensitivity of candida to Mystatin (30 mg) was 12 mm. Nanocomposites have improved nanoparticles in antibacterial and antifungal Activities as confirmed by result of XRD and TEM.Fig. 9 Image of the CuO, ZnO, Co3O4 nanoparticals and CuO-ZnO-Co3O4 nanocomposite inhibition zones against Candida.

Fig. 9

Fig. 10 Antifungal activity of the CuO, ZnO,Co3O4 and CuO-ZnO-Co3O4 nanocomposite and an antifungal against pathogenic Candida.

Fig. 10

Reactive oxygen species (ROS) photo generation on the surface of metal-oxide nanocomposites has been the subject of numerous studies [55]. Super oxide anions (O2−) and CuO-ZnO-Co3O4 nanocomposite oxidation produces Cu2+, Zn2+, and Co2+ ions, which aid in their diffusion into the biological system or cause oxidative stress and reactive oxygen species (ROS), which alter membrane permeability, harm proteins, lipids, DNA/RNA, and eventually lead to cytotoxicity in prokaryotic cells [56,57]. The more potent oxidizing agents (OH) among the ROS are hydroxyl radicals and hydrogen peroxide (H2O2). By directly penetrating the cell membrane of the bacteria, they damage them by preventing cell growth. Additional mechanisms are also utilized to mediate the antibacterial activity. Nanocomposite damages the bacterial cell membrane and binds to the mesosome. Due to the cell death caused by these intracellular functional changes, oxidative stress is introduced [[58], [59], [60]].

The negative-charged cell membranes and the heavy metal ions Cu2+, Zn2+, and Co2+ with positive charges attract each other when they come into contact with the microbe's cell membranes (Fig. 11). Cu2+, Zn2+, and Co2+ then penetrate the cell membrane and interact with the thiol groups (-SH) of the proteins that are present on the bactericidal cell surface. The proteins are rendered inactive by the nanomaterials, and the membrane permeability is reduced, which results in the microbe's death. Furthermore, the surface area of nanocomposites has a significant impact on the chemical interaction between them and the cell membrane, and the same thing happens in fungal cells [61]. We choose the most prevalent bacteria through our own process of selectivity. According to recent studies, nanocomposite exhibits greater effectiveness. While it comes to treating the most contagious strains, the treatment (Nanocomposite) is more effective than other nanoparticle because it can cure the infection effectively and efficiently [62].Fig. 11 Mechanism of antibacterial and antifungal activity of CuO,ZnO,Co3O4 nanoparticals and CuO- ZnO-Co3O4 nanocomposite.

Fig. 11

4 Conclusions

The co-precipitation method was utilized to prepare pure CuO, ZnO, Co3O4 nanoparticles and CuO-ZnO-Co3O4 mixed ternary oxide nanocomposite. The XRD pattern revealed that nanocomposite has monoclinic CuO, hexagonal ZnO, and cubic Co3O4 structures. The nanocomposite particle size revealed by TEM image is 18.1 nm. SAED results were consistent with the indexing of XRD peaks and demonstrate the polycrystalline nature of the samples. The results of XRD were also in good agreement with TXRF results. From the results of the zeta potential, CuO nanoparticles were more stable than Co3O4 nanoparticles and CuO-ZnO-Co3O4 nanocomposite, while ZnO had poor stability. The optical band gap of nanocomposite was 1.3 eV. The antimicrobial and antifungal properties of nanocomposite are demonstrated against both Gram-positive and Gram-negative bacteria. The results showed that CuO-ZnO-Co3O4 nanocomposite has good antibacterial and antifungal properties. We recommend that metal oxides that we produce be applied to animals after injecting them with bacteria and fungi. Then notice the side effects and add some physical measurements, such as photocatalytic.

Data availability statement

Data will be made available on request.

CRediT authorship contribution statement

Shadha Nasser Aziz: Writing – original draft, Software, Formal analysis, Data curation. A.M. Abdulwahab: Supervision, Software, Project administration, Methodology. Thana Shuga Aldeen: Writing – review & editing, Supervision, Formal analysis. Dheyazan Mohammed Ali Alqabili: Formal analysis.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The authors are grateful for Guinness University of Science and Technology, and 10.13039/501100020401 Thamar University , Thamar city, Republic of Yemen for their support in helping us with sample processing. The authors are grateful for Dr. Majid Al-Jaradi for assisting in biological experiments. A lot of thanks for New Med Lab Specialized Laboratories and Modern Bainon Laboratory, Thamar City, Republic of Yemen.
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References

1 Yufanyi D.M. Tendo J.F. Ondoh A.M. Mbadeam J.K. CdO nanoparticles by thermal decomposition of a cadmium-hexamethylenetetramine complex J. Mater. Sci. Res. 3 3 2014 1 10.5539/jmsr.v3n3p1
2 Munawar T. Iqbal F. Yasmeen S. Mahmood K. Hussain A. Multi metal oxide NiO-CdO-ZnO nanocomposite–synthesis, structural, optical, electrical properties and enhanced sunlight driven photocatalytic activity Ceram. Int. 6 2 2020 2421 2437 10.1016/j.ceramint.2019.09.236
3 Al-Hada N.M. Saion E.B. Shaari A.H. Kamarudin M.A. Flaifal M.H. Ahmad S.H. Gene A. A facile thermal-treatment route to synthesize the semiconductor CdO nanoparticles and effect of calcination Mater. Sci. Semicond. Process. 26 2014 460 466 10.1016/j.mssp.2014.05.032
4 Balamurugan S. Balu A.R. Narasimman V. Selvan G. Usharani K. Srivind J. Suganya M. Manjula N. Rajashree C. Nagarethinam V.S. Multi metal oxide CdO–Al2O3–NiO nanocomposite—synthesis, photocatalytic and magnetic properties Mater. Res. Express 6 1 2018 015022
5 Ge X. Ren C. Ding Y. Chen G. Lu X. Wang K. Ren F. Yang M. Wang Z. Li J. An X. Qian B. Leng Y. Micro/nano-structured TiO2 surface with dual-functional antibacterial effects for biomedical applications Bioact. Mater. 4 2019 346 357 10.1016/j.bioactmat.2019.10.006 31720491
6 Akpan U. Hameed B. The advancements in sol–gel method of doped-TiO2 photocatalysts Appl. Catal. Gen. 375 1 2010 1 11 10.1016/j.apcata.2009.12.023
7 Rajesh D. Lakshmi B.V. Sunandana C.S. Two-step synthesis and characterization of ZnO nanoparticles Phys. B Condens. Matter 407 23 2012 4537 4539 10.1016/j.physb.2012.07.050
8 Karthik K. Dhanuskodi S. Gobinath C. Prabukumar S. Sivaramakrishnan S. Photocatalytic and antibacterial activities of hydrothermally prepared CdO nanoparticles J. Mater. Sci. Mater. Electron. 28 2017 11420 11429
9 Revathi V. Karthik K. Microwave assisted CdO–ZnO–MgO nanocomposite and its photocatalytic and antibacterial studies J. Mater. Sci. Mater. Electron. 29 2018 18519 18530 10.1007/s10854-018-9968-1
10 Li F. Wang H. Wang L. wang J. Magnetic properties of ZnFe2O4 nanoparticles produced by a low-temperature solid-state reaction method J. Magn. Magn Mater. 309 2 2007 295 299 10.1016/j.jmmm.2006.07.012
11 Tazikeh S. Akbari A. Talebi A. Talebi E. Synthesis and characterization of tin oxide nanoparticles via the Co-precipitation method Materials Science-Poland 32 2014 98 101
12 Rashad M. Zaki Z.I. El-Shall H. A novel approach for synthesis of nanocrystalline MgAl 2 O 4 powders by co-precipitation method J. Mater. Sci. 44 2009 2992 2998
13 Ren G. Hu D. Cheng E.W.C. Reus M.A. Reip P. Allaker R.P. Characterisation of copper oxide nanoparticles for antimicrobial applications Int. J. Antimicrob. Agents 33 6 2009 587 590 10.1016/j.ijantimicag.2008.12.004 19195845
14 Borkow G. Gabbay J. Copper, an ancient remedy returning to fight microbial, fungal and viral infections Curr. Chem. Biol. 3 3 2009 272 278
15 Raghupathi K.R. Koodali R.T. Manna A.C. Size-dependent bacterial growth inhibition and mechanism of antibacterial activity of zinc oxide nanoparticles Langmuir 27 7 2011 4020 4028 10.1021/la104825u 21401066
16 Applerot G. Lellouche J. Perkas N. Nitzan Y. Gedanken A. Banin E. ZnO nanoparticle-coated surfaces inhibit bacterial biofilm formation and increase antibiotic susceptibility Rsc Advances 2 6 2012 2314 2321
17 Tan E.P. Djearamane S. Wong L.S. Rajamani R. Antony A.C.T. Subbaih S.K. Janakiraman A.K. Aminuzzaman M. Subramaniyan V. Sekar M. Selvaraj S. An in vitro study of the antifungal efficacy of zinc oxide nanoparticles against Saccharomyces cerevisiae Coatings 12 12 2022 1988 10.3390/coatings12121988
18 Selvanathan V. Aminuzzaman M. Tan L.X. Win Y.F. Cheah E.S. Heng M.H. Tey L. Arullappan S. Algthami N. Alharthi S.S. Sultana S. Shahiduzzaman M. Abdullah H. Aktharuzzaman M. Synthesis, characterization, and preliminary in vitro antibacterial evaluation of ZnO nanoparticles derived from soursop (Annona muricata L.) leaf extract as a green reducing agent J. Mater. Res. Technol. 20 2022 2931 2941 10.1016/j.jmrt.2022.08.028
19 Franci G. Falanga A. Galdiero S. Palomba L. Rai M. Morelli G. Galdiero M. Silver nanoparticles as potential antibacterial agents Molecules 20 5 2015 8856 8874 10.3390/molecules20058856 25993417
20 Lemire J.A. Harrison J.J. Turner R.J. Antimicrobial activity of metals: mechanisms, molecular targets and applications Nat. Rev. Microbiol. 11 6 2013 371 384 23669886
21 Dadi R. Azouani R. Traore M. Mielcarek C. Kanaev A. Antibacterial activity of ZnO and CuO nanoparticles against gram positive and gram negative strains Mater. Sci. Eng. C 104 2019 109968 10.1016/j.msec.2019.109968
22 Nagore P. Ghotekar S. Mane K. Ghoti A. Bilal M. Roy A. Structural properties and antimicrobial activities of Polyalthia longifolia leaf extract-mediated CuO nanoparticles BioNanoScience 11 2021 579 589
23 Azam A. Ahmed A.S. Oves M. Khan M.S. Habib S.S. Memic A. Antimicrobial activity of metal oxide nanoparticles against Gram-positive and Gram-negative bacteria: a comparative study Int. J. Nanomed. 2012 6003 6009 10.2147/IJN.S35347
24 Das D. Saikia B.J. Synthesis, characterization and biological applications of cobalt oxide (Co3O4) nanoparticles Chemical Physics Impact 6 2023 100137 10.1016/j.chphi.2022.100137
25 Sharma D. Rajput J. Kaith B.S. Kaur M. Sharma S. Synthesis of ZnO nanoparticles and study of their antibacterial and antifungal properties Thin Solid Films 519 3 2010 1224 1229 10.1016/j.tsf.2010.08.073
26 Khalaji A. Pazhand Z. Kiani K. Machek P. Jarosova M. Mazandarani R. CuO nanoparticles: preparation, characterization, optical properties, and antibacterial activities J. Mater. Sci. Mater. Electron. 31 2020 11949 11954
27 Haq S. Rshid M. Menaa F. Shahzad N. Shahzad M.I. Alfaifi S.Y. Madkhali O. Aljabri M. Ashravi M. Tayeb R. Rahmani M. Antibacterial and antioxidant screening applications of reduced-graphene oxide modified ternary SnO2-NiO-CuO nanocomposites Arab. J. Chem. 16 8 2023 104917 10.1016/j.arabjc.2023.104917
28 Dias L.F.G. pimentel G.J.C. Rheinheimer J.P.C. Gomes O.P. Almeida B.G.D. Volanti D.P. Almeida M.T.G. Lisboa-Filho P.N. Synthesis and characterization of CuO-MgO-ZnO and CuO-Co3O4-CeO2 Discover Materials 3 1 2023 27 10.1007/s43939-023-00064-4
29 Kannan K. Radhika D. Gnanasangeetha D. Lakkaboyana S.K. Sadasivuni K.K. Gurushankar K. Hanafiah M.M. Photocatalytic and antimicrobial properties of microwave synthesized mixed metal oxide nanocomposite Inorg. Chem. Commun. 125 2021 108429 10.1016/j.inoche.2020.108429
30 Alam M.W. Al Qahtani H.S. Souayeh B. Ahmed W. Albalawi H. Farhan M. Abuzir A. Naeem S. Novel copper-zinc-manganese ternary metal oxide nanocomposite as heterogeneous catalyst for glucose sensor and antibacterial activity Antioxidants 11 6 2022 1064 10.3390/antiox11061064 35739961
31 GuzmÃ L. Ramirez B.S. Maribel C.F. Pescador M.G. Cruz F.J.M. Low accuracy of the McFarland method for estimation of bacterial populations Afr. J. Microbiol. Res. 12 31 2018 736 740 10.5897/AJMR2018.8893
32 Raba-Páez A.M. Malafatti J.O. Parra-Vargas C.A. Paris E.C. Rincon-Joya M. Effect of tungsten doping on the structural, morphological and bactericidal properties of nanostructured CuO PLoS One 15 9 2020 e0239868 10.1371/journal.pone.0239868
33 Poirel L. Jayol A. Nordmann P. Polymyxins: antibacterial activity, susceptibility testing, and resistance mechanisms encoded by plasmids or chromosomes Clin. Microbiol. Rev. 30 2 2017 557 596 10.1128/cmr.00064-16 28275006
34 Wolfensberger A. Sax H. Weber R. Zbinden R. Kuster S. Hombach M. Change of antibiotic susceptibility testing guidelines from CLSI to EUCAST: influence on cumulative hospital antibiograms PLoS One 8 11 2013 e79130 10.1371/journal.pone.0079130
35 Paraguay-Delgado F. Hermida-Montero L.A. Morales-Mendoza J.E. Duran-Barradas Z. Mtz-Enriques A. Parioa N. Photocatalytic properties of Cu-containing ZnO nanoparticles and their antifungal activity against agriculture-pathogenic fungus RSC Adv. 12 16 2022 9898 9908 35424965
36 Sarfraz M. Ahmed N. Ul- Haq Khizar Shahida S. Khan M.A. Structural optical and magnetic properties of transition metal doped ZnO magnetic nanoparticles synthesized by sol-gel auto-combustion method Materials Science-Poland 37 2 2019 280 288 http://www.materialsscience.pwr.wroc.pl/
37 Diallo A. Beye A.C. Doyle T.B. Park E. Maaza M. Green synthesis of Co3O4 nanoparticles via Aspalathus linearis: physical properties Green Chem. Lett. Rev. 8 3–4 2015 30 36 10.1080/17518253.2015.1082646
38 Mustapha S. Ndamitso M.M. Abdulkareem A.S. Tijani J.O. Shuaib D.T. Mohammed A.K. Sumaila A. Comparative study of crystallite size using Williamson-Hall and Debye-Scherrer plots for ZnO nanoparticles Adv. Nat. Sci. Nanosci. Nanotechnol. 10 4 2019 045013
39 Chan Y.B. Aminuzzaman M. Rahman M.K. Win Y.F. Sultana S. Cheah S. Watanabe A. Wong L.S. Guha S.K. Djearamane S. Rajendran V. Rajendran V. Akhtaruzzaman M. Tey L. Green synthesis of ZnO nanoparticles using the mangosteen (Garcinia mangostana L.) leaf extract: comparative preliminary in vitro antibacterial study Green Process. Synth. 13 1 2024 20230251 10.1515/gps-2023-0251
40 Miled I.B. Jlassi M. Sta I. Dhaouadi M. hajji M. Mousdis G. Kompitsas M. Ezzaouia H. Structural, optical, and electrical properties of cadmium oxide thin films prepared by sol–gel spin-coating method J. Sol. Gel Sci. Technol. 83 2017 259 267
41 Alnehia A. Al-Hammadi A.H. Al-Sharabi A. Alnahari H. Optical, structural and morphological properties of ZnO and Fe+ 3 doped ZnO-NPs prepared by Foeniculum vulgare extract as capping agent for optoelectronic applications Inorg. Chem. Commun. 143 2022 109699 10.1016/j.inoche.2022.109699
42 Al-Sharabi A. Sada'a K.S.S. AL-Osta A. Abd-Shukor R. Structure, optical properties and antimicrobial activities of MgO–Bi2− x Cr x O3 nanocomposites prepared via solvent-deficient method Sci. Rep. 12 1 2022 10647 10.1038/s41598-022-14811-9
43 Ishfaq M. Hassan W. Sabir M. Somaily H.H. Hachim S.K. Kadhim Z.J. Lafta H.A. Alnassar Y.S. Rheima A.M. Ejaz S.R. Aadil M. Wet-chemical synthesis of ZnO/CdO/CeO2 heterostructure: a novel material for environmental remediation application Ceram. Int. 48 23 2022 34590 34601 10.1016/j.ceramint.2022.08.046
44 Qamar M.A. Shahid S. Javed M. Iqbal S. Sher M. Akbar M.B. Highly efficient g-C3N4/Cr-ZnO nanocomposites with superior photocatalytic and antibacterial activity J. Photochem. Photobiol. Chem. 401 2020 112776 10.1016/j.jphotochem.2020.112776
45 Parsai T. Kumar A. Stability and characterization of mixture of three particle system containing ZnO-CuO nanoparticles and clay Sci. Total Environ. 740 2020 140095 10.1016/j.scitotenv.2020.140095
46 Sati P. Shenda R.C. Ramaprabhu S. An experimental study on thermal conductivity enhancement of DI water-EG based ZnO (CuO)/graphene wrapped carbon nanotubes nanofluids Thermochim. Acta 666 2018 75 81 10.1016/j.tca.2018.06.008
47 Henderson R. Parsons S.A. Jefferson B. Successful removal of algae through the control of zeta potential Separ. Sci. Technol. 43 7 2008 1653 1666 10.1080/01496390801973771
48 Khan I. Khan I. Usman M. Imran M. Saeed K. Nanoclay-mediated photocatalytic activity enhancement of copper oxide nanoparticles for enhanced methyl orange photodegradation J. Mater. Sci. Mater. Electron. 31 2020 8971 8985 10.1007/s10854-020-03431-6
49 Hussein O.N. AL-Jawad S.M.H. Natheer, Efficient antibacterial activity enhancement in Fe/Mn co-doped CuS nanoflowers and nanosponges Bull. Mater. Sci. 46 3 2023 139 10.1007/s12034-023-02964-w
50 Aldeen T.S. Mohamed H.E.A. Maaza M. ZnO nanoparticles prepared via a green synthesis approach: physical properties, photocatalytic and antibacterial activity J. Phys. Chem. Solid. 160 2022 110313 10.1016/j.jpcs.2021.110313
51 Al-Ariki S. Yahya N.A.A. Al-A'nsi S.A. Jumali M.H.H. Jannah A.N. Abd-Shukor R. Synthesis and comparative study on the structural and optical properties of ZnO doped with Ni and Ag nanopowders fabricated by sol gel technique Sci. Rep. 11 1 2021 11948 10.1038/s41598-021-91439-1
52 Makhlouf S.A. Bakr Z.H. Aly K.I. Moustafa M.S. Structural, electrical and optical properties of Co3O4 nanoparticles Superlattice. Microst. 64 2013 107 117
53 Abdulwahab A. AL-Adhreai A.A. Ahmed A.A.A. Influence of Ni-Co dual doping on structural and optical properties of CdSe thin films prepared by chemical bath deposition method Optik 236 2021 166659 10.1016/j.ijleo.2021.166659
54 Wright J.T. Su D. Buuren T.V. Meulenberg R.W. Electronic structure of cobalt doped CdSe quantum dots using soft X-ray spectroscopy J. Mater. Chem. C 2 39 2014 8313 8321
55 Ezhilarasi A.A. Vijaya J.J. Kaviyarasu K. Maaza M. Ayeshamariam A. J Kennedy L. Green synthesis of NiO nanoparticles using Moringa oleifera extract and their biomedical applications: cytotoxicity effect of nanoparticles against HT-29 cancer cells J. Photochem. Photobiol. B Biol. 164 2016 352 360 10.1016/j.jphotobiol.2016.10.003
56 Zulfiqar H. Zafar A. Rasheed M.N. Ali Z. Mehmood K. Mazher A. Hasan M. Mahmooed N. Synthesis of silver nanoparticles using Fagonia cretica and their antimicrobial activities Nanoscale Adv. 1 5 2019 1707 1713 36134229
57 Hasan M. Altaf M. Zafar A. Hassan S.G. Ali Z. Mustafa G. Munawar T. Saif M.S. Tariq T. Iqbal F. Khan M.W. Mahmood A. Mahmmod N. Shu X. Bioinspired synthesis of zinc oxide nano-flowers: a surface enhanced antibacterial and harvesting efficiency Mater. Sci. Eng. C 2021 111280 10.1016/j.msec.2020.111280
58 Karthik K. Dhanuskodi S. Gobinath C. Prabukumar S. Sivaramakrishnan S. Multifunctional properties of microwave assisted CdO–NiO–ZnO mixed metal oxide nanocomposite: enhanced photocatalytic and antibacterial activities J. Mater. Sci. Mater. Electron. 29 2018 5459 5471 10.1007/s10854-017-8513-y
59 Al-Mushki A.A. Ahmed A.A.A. Abdulwahab A.M. Qaid S.A.S. Alzayed N.S. Shahabuddin M. Abduljalil J.M. Saad F.A.A. Effect of the molar ratio of (Ni2+ and Fe3+) on the magnetic, optical and antibacterial properties of ternary metal oxide Cdo–Nio–Fe2o3 nanocomposites Sci. Rep. 13 1 2023 9021 10.1038/s41598-023-36262-6 37270550
60 Ahmed A.A.A. AL-Mushki A.A.A. AL-Asbahi B.A. Abdulwahab A.M. Abduljalil J.M.A. Saad F.A.A. Qaid S.M.H. Ghaithan H.M. Farooq W.A. Omar A. Effect of ethylene glycol concentration on the structural and optical properties of multimetal oxide CdO–NiO–Fe2O3 nanocomposites for antibacterial activity J. Phys. Chem. Solid. 155 2021 110113 10.1016/j.jpcs.2021.110113
61 Zhang R. Cui Y. Cheng M. Guo Y. Wang X. Wang J. Antifungal activity and mechanism of cinnamon essential oil loaded into mesoporous silica nanoparticles Ind. Crop. Prod. 171 2021 113846 10.1016/j.indcrop.2021.113846
62 Qasim S. Zafar A. Saif M.S. Ali Z. Nazar M. Waqas M. Tariq T. Hassan S.G. Iqbal F. Shu X. Hasan M. Green synthesis of iron oxide nanorods using Withania coagulans extract improved photocatalytic degradation and antimicrobial activity J. Photochem. Photobiol. B Biol. 204 2020 111784 10.1016/j.jphotobiol.2020.111784
