Rapid photocatalytic dye degradation, enhanced antibacterial and antifungal activities of silver stacked zinc oxide garnished on carbon nanotubes

A composite of Zinc oxide loaded with 5-weight % silver decorated on carbon nanotubes (Ag-loaded ZnO: CNT) was synthesized using a simple refluxed chemical method. The influence of deviation in the weight % of carbon nanotube loading on photocatalytic dye degradation (methylene blue and rose bengal) and antibiotic (antimicrobial and antifungal) performance was investigated in this study. The light capture ability of Ag-loaded ZnO:CNT in the visible region was higher in photocatalytic activity than that of Ag-loaded ZnO and ZnO:CNT. The bandgap of the Ag-loaded ZnO: CNT was tuned owing to the surface plasmon resonance effect. The photocatalytic degradation investigations were optimized by varying the wt% in CNTs, pH of dye solution, concentration of the dye solution, and amount of catalytic dose. Around 100% photocatalytic efficiency in 2 min against MB dye was observed for Ag doped ZnO with 10 wt% CNT composite at pH 9, at a rate constant 1.48 min−1. Bipolaris sorokiniana fungus was first time tested against a composite material, which demonstrated optimum fungal inhibition efficiency of 48%. They were also tested against the bacterial strains Staphylococcus aureus, Bacillus cerius, Proteus vulgaris, and Salmonella typhimurium, which showed promising antibacterial activity compared to commercially available drugs. The composite of Ag doped ZnO with 5 wt% CNT has shown competitive zone inhibition efficacy of 21.66 ± 0.57, 15.66 ± 0.57, 13.66 ± 0.57 against bacterial strains Bacillus cerius, Proteus vulgaris, and Salmonella typhimurium which were tested for the first time against Ag-loaded ZnO:CNT.


Antifungal activity measurement
The antifungal activity of the silver-loaded zinc oxide: carbon nanotube was evaluated using the agar diffusion process, as previously described 29 .To perform this test, potato dextrose agar (PDA) medium was mixed into 0.1 L of double distilled water and boiled until completely dissolved.The PDA and glass Petri dishes were autoclaved for 30 min at 15 Pa of pressure to sterilize them, and the PDA medium was spread into the Petri dishes using a laminar flow chamber.Following the solidification of the medium, 20 mg of the produced material was placed on the plate.The center of the Petri plate was then injected with a fungal disc from Bipolaris sorokiniana 29 .The potato dextrose agar disc was removed from the center using a sterile cork borer for inoculation.A control without Ag-loaded ZnO:CNT composites was used for comparison with incubation of the plates for 72 h at 25 °C.The growth of the fungal zone was also observed.We measured the diameter of such inhibitors to determine their antifungal activity using the poisoned food approach 31 .

Antimicrobial activity measurement
During the water refinement process, several supplementary toxins and organic pollutants are present in sewage.These toxic materials contain bits and pieces of microorganisms, and it was previously discovered that organic metals are primarily responsible for the proliferation of dangerous bacteria in water 32 .Consequently, it was discovered that photocatalysts possess the potential to allow microbial pollutants to reside on them 33 .Examining the antibacterial activity of Ag-loaded ZnO:CNT (50 µg/mL) and commercial antibiotics (50 µg/mL), a notable zone of inhibition was found.Microbial cultures were cultivated in inocula using a sterile saline solution.Nutrient agar plates were used as substrates for the development of bacteria.Staphylococcus aureus was allowed to grow on sterile savored agar plates; similarly, Bacillus cereus, Proteus vulgaris, and Salmonella typhimurium cultures were allowed to thrive on clean nutrient agar plates.Powdered 5CNT, 10CNT, 15CNT, and 20CNT were mixed with sterile distilled water and dimethyl sulfoxide (DMSO) using a micropipette.To track the antibacterial activity, the plates were incubated for twenty-four hours at 37 °C34 .

Photodegradation activity
We generated dye solutions of various concentrations in DDW to evaluate the photocatalytic degradation activity, and the sample was investigated using a UV-visible study, which yielded the absorbance of an unadulterated dye solution of a given concentration.A fixed number of catalyst samples were combined with MB and RB dye solutions.The solutions were held in a gloomy environment for 30 min with regular agitation to avoid light interactions and to sustain adsorption/desorption symmetry among the photocatalyst surfaces and dye molecules 35 .The solutions were then exposed to visible light to evaluate their photocatalytic degradation ability.Small samples were taken at regular intervals for UV-Vis measurements until the total disintegration of the dye solution was observed.The fading of the characteristic absorbance peak from the UV-Vis experiments confirmed dye degradation.By pulling out aliquots for UV-Vis spectroscopic measurement at time intervals of 5 min for each sample, the absorbance maxima of MB and RB were observed at 664 nm and 546 nm, respectively.

X-ray diffraction analysis
Figure 1 shows the X-ray diffraction pattern array of the 5 wt% Ag loaded ZnO composed with (5 to 20) wt% CNT's.The major ZnO peaks have hexagonal phases, which is in good agreement with JCPDS Card No. 653411 for all samples (indicated by # mark in Fig. 1).As we have amalgamated Ag with ZnO, the (111) and ( 200) peaks (indicated by * mark in Fig. 1) corresponding to Ag are observed with low-intensity minor phase development, as reported in our previous work 36 .Silver was found in interstices as well as in substitutional Zn sites, as reported elsewhere.The existence of the (002) carbon peak was (indicated by □ mark in Fig. 1) also observed in all the samples owing to composite formation with CNTs.Other diffraction peaks show no significant change as a result of CNT integration, which is consistent with the physical interaction of CNT with the Ag-ZnO array 37 .The integration of CNTs into Ag-loaded ZnO precludes the secondary phase formation in the XRD configuration of the materials.The Scherrer equation was employed to calculate the microstrain, dislocation density, and average crystallite size for the (100), ( 002), ( 101), ( 102), ( 110), ( 103), (200), and (112) peaks of ZnO, as summarized in Table 1.
The microstrain and dislocation density were the highest for 10CNT, and the mean crystallite size was 19 nm for 10CNT.This could have been caused by the occurrence of silver ions in the ZnO array hindering the formation of crystal grains, and resistance to grain boundary growth was created, possibly as a result of the Zinner-Pinning effect 38 .

Optical analysis
The absorption spectra of the Ag-loaded ZnO/CNT composites are shown in the inset of Fig. 2a.Owing to the relocation of charges from the valence band to the conduction band of ZnO, a strong absorption edge was observed in the UV region (200-420 nm) 6,39 .As shown in Fig. 2a, the Tauc plot was used to measure the bandgap energy (Eg) of the composites.The bandgap energies (Eg) of 5CNT, 10CNT, 15CNT, and 20CNT were found to be around 3.25 eV at the absorbance maxima obtained of 359 nm.The accumulation of silver ions produces substantial alterations in the absorption spectra of ZnO, causing high absorbance in the complete visible spectrum in the form of a bulge, owing to the surface plasmon band 40 .The increase in luminescence can be caused by surface plasmon scattering 4 .At the interface of Ag and ZnO in the array, the localized electric field associated with metal ions is amplified, inducing surface plasmon excitation in the Ag nanoparticles positioned at the interface, which enhances the visible absorption of light photons 41 .As a result, the existence of Ag nanoparticles on ZnO materials causes an increase in visible light capture due to the plasmon band on the Ag surface 42 .
The conduction band potential and valance band potential of Ag-ZnO were measured by using the Mulliken electronegativity theory 13 (1)  www.nature.com/scientificreports/where, X is the absolute electronegativity of the semiconductor and for ZnO it is 5.76 eV (vs NHE), E g is the band gap energy of the semiconductor, E VB is the valence band edge potential of semiconductor and E e is the energy of free electrons and it is ~ 4.5 eV (vs NHE) and E CB shows the conduction band edge potential 43 .The calculated values of valence band and conduction band potentials were 2.88 eV (vs NHE) and − 0.37 eV (vs NHE) respectively.Additionally, the work functions of Ag and ZnO are 4.3 and 5.2 eV, respectively; thus, the transmission of an electron from Ag to ZnO is suitable, which is in good agreement with photoluminescence spectroscopy studies 44,45 .The work function of functionalized MWCNT is 5.1 eV 46 .Also, it is demonstrated that MWCNT turns to be photosensitizer by captivating light so that they get excited to higher energy level leading to electron transfer.Photoluminescence spectroscopy is a broad technique used to investigate the reunion of light-induced charge carriers in semiconductors 47,48 .The simultaneous recombination of photogenerated electron-hole pairs and radiation produces PL spectra with small PL intensity, indicating a sluggish reunion rate 12 Here, we recorded the PL spectra of all composite samples under ambient thermal conditions, as shown in Fig. 2b, when excited at 320 nm.The PL spectrum showed stronger absorption at 380 nm and poorer absorption at 354 nm in the UV region 49,50 .The emission characteristics of all samples are comparable, with the peak at approximately 530 nm showing lowered intensities due to the transfer of electrons from the Zn i level positioned beneath the conduction band to the valence band, signifying quenching of PL emission 51 .The plasmonic absorption of Ag nanoparticles may be responsible for the decrease in the visual emission intensity of the catalysts 49,50,52,53 .UV radiation due to near-band emission can be initiated by the wide band gap of ZnO.Furthermore, a couple of frail bands in the visible area near 430-440 nm could be caused by surface flaws of ZnO nanoparticles and bound pairs of charge carriers.Hence, it extends its support to the notion of integration of Ag nanoparticles and CNTs, which increases the lifetime of photogenerated charge carriers and subsequently raises the photocatalytic activity owing to lowered surface deficiencies in the Ag-loaded ZnO:CNT composite structure.
FT-IR spectra depict information about a specific substance, functional groups, molecular shape, and inter-/ intramolecular interactions.We employed the room-temperature KBr pellet method to study the FT-IR spectra www.nature.com/scientificreports/ of the 5CNT, 10CNT, 15CNT, and 20CNT nanocomposites, as depicted in Fig. 2c.The spectra were run over the wave number range of 400-4000 cm −1 .The absorption band between 2850 and 2920 cm −1 was found to be an asymmetric stretching mode for the C-H bond, which may be caused by sodium lauryl sulfate residues.Figure 2d shows the EDS analysis of 5CNT, 10CNT, 15CNT, and 20CNT composites.
The absorption band at 2350 cm −1 was discovered to correspond to CO 2 .In addition, the H-O-H bending vibration of water was observed at 1530 cm −1 , while the band near 1030 cm −1 represented the asymmetric stretching of C-O 54 .The vibration modes of Zn-O correspond to the bands in the low wavenumber area of 435 cm −155 .This implies that the hydroxyl and carboxylic groups present on the exterior of the catalysts improve photocatalytic activity 56 .

Morphological analysis
FESEM and EDS studies FESEM images of the 5CNT, 10CNT, 15CNT, and 20CNT composites at 500 nm magnification are shown in Fig. 3.It is found that there is an agglomeration of Ag-loaded ZnO nanoparticles displaying cauliflower-like morphology.Each FESEM micrograph shows varying particle sizes ranging from 60 to 90 nm, which may be due to the change in the weight percentage contribution of CNT to the material.Larger particles occur owing to the agglomeration effect and the concentration of nucleation sites.The average particle size and diameter of the CNT calculated using the FESEM images were approximately 75 nm and 80 nm, respectively.Figure 2d.shows the EDS spectrum for 5CNT, 10CNT, 15CNT and 20CNT.The composition and distribution of Ag-loaded ZnO:CNT composite nanoparticles are indicated by EDS mapping, which shows the even distribution of CNTs in the Ag Ag-loaded ZnO array.The spreading of the Zn and oxygen peaks in the EDS mapping confirms the purity of ZnO.The presence of Ag and carbon peaks in the Ag-loaded ZnO:CNT arrangement supplements the composite development in the matrix 57 .

X-ray photoelectron spectroscopy (XPS) studies
Elemental composition and oxidation states of Ag doped ZnO/(10%)CNT were studied with the help of x-ray photoelectron spectroscopy (Fig. 4).As shown in Fig. 4a, the C 1s spectrum shows two peaks observed at binding energies of 284.4,and 285.4 eV that can link to C=C, and C-C respectively 58,59 .The peak at 284.4 is due to sp 2 hybridized carbon atoms whereas different functional groups such as carboxyl and hydroxyl are attached to the surface of CNT are responsible for the peak at higher binding energy of 285.4 correspond to the sp 3 hybridized carbon atoms 60 .Moreover, Ag 3d spin-orbit coupling is apparent from Fig. 4b, where two discrete peaks observed at binding energies 368.3 and 374.3 eV accredited to Ag 3d 5/2 and Ag 3d 3/2 , respectively.Both peaks have 6 eV difference in their binding energies approves the presence of the Ag in the metallic nature over the surface of the ZnO 61 .Zn with 2 + valance state in ZnO is confirmed with Fig. 4c displaying the two binding energy peaks of Zn-2p 3/2 and Zn-2p 1/2 with energy difference of 23.1 eV corresponding to spin-orbit doublet.Also the O1s spectrum shown two peaks at 530.2 and 531.7 eV (Fig. 4d).The peak at 530.2 eV was due to O 2 -ions attached with zinc in ZnO crystal structure, and the peak at 531.7 can be attributed to oxygen deficiencies or presence of hydroxyl and carboxyl group due to surface defects 62 .

Photocatalytic studies
The photocatalytic activity of the synthesized nanohybrid catalysts was initially studied in the presence of visible light with 10 ppm methylene blue (MB) and 10 ppm rose bengal (RB) as symbolic pollutants, as shown in Figs. 5  and 6.In the current study, we prepared an array of stock solutions of MB and RB dyes in 1000 ml DDW and stored them in the dark.Catalysts 5CNT, 10CNT, 15CNT, and 20CNT have shown dye disintegration efficiencies of 78%, 99%, 98%, and 93% within 20 min of visible light irradiation against 10 ppm MB dye solution, as shown in Fig. 7a and c.Similarly, 80%, 99%, 91%, and 74% dye degradation efficiency within 20 min of visible light irradiation against 10 ppm RB dye solution, respectively, as shown in Fig. 7b and d.The photocatalytic degradation efficiency was calculated using Eq. ( 3) 63 .
where C 0 is the absorbance at time' t = 0 min and C t is the absorbance at time 't' min.Thus, the 10CNT catalysts showed optimized results for the disintegration of all dyes.The stability of 10CNT photocatalysts was studied by repeating the degradation studies, which have prolifically shown 91% efficiency even after four reusability cycles.The variation in the pH value of the dye solution was also explored during this study for the 10 ppm MB dye solution, and the photocatalytic degradation experiment was performed with pH values ranging from 6 to 10.We also carried out variations in catalytic doses from 0.6 g/liter, 0.8 g/liter, 1 g/ liter, and 1.2 g/liter loading of photocatalysts against 10 ppm MB dye solutions at an optimum pH value-9 in the presence of visible-light irradiation.A spectroscopic study of fixed time interval samples was carried out using UV-Vis spectroscopy, which revealed that the preliminary absorption peak at 664 nm gradually declined with time.This indicates that the MB dye solution crumbled into constituents such as CO 2 , H 2 O, and other bland organic waste products 64 (Table 2).
The proposed mechanism of the electron-hole pair generation and photocatalytic degradation by Ag doped ZnO:CNT is as shown below 29,30

Parameter variation in photocatalytic studies
In this study, we explored aspects such as variations in dye concentration, pH, and catalytic dose to optimize these parameters.The dye concentration was optimized by studying 10, 30, and 50 ppm solutions of MB dye against 5CNT, 10CNT, 15CNT, and 20CNT catalysts.It was observed that with an increase in the concentration of the dye, there was an upsurge in the time required for photocatalytic disintegration, as shown in Fig. 8a,b, with significant variances as matched with 30 ppm and 50 ppm solutions.Thus, the dye concentration is inversely proportional to the dye degradation efficiency of the catalyst.The catalyst concentration inhibited dye degradation.The 10CNT catalysts have shown 99% degradation efficiency at an MB dye concentration of 10 ppm.
Based on this information, we tried varying the pH and catalytic dosage of the 10 ppm MB dye solution against 10CNT catalysts.The consequence of the variation in the pH of 10 ppm MB dye solution on the disintegration performance was calculated using 100 mg of 10CNT catalyst, as displayed in Fig. 8c.The initial pH of the MB solution was ~ 6.9.With an increase in pH, there was considerable reduction in photocatalytic degradation time Here, the pH for MB was varied from 6 to 10, showing the best result at pH 9, with 100% degradation within 2 min of visible light irradiation 65 .( 9) www.nature.com/scientificreports/Hence, we performed photocatalytic degradation of MB dyes using four different weight ratios of the 10CNT catalysts, that is, 0.6, 0.8, 1, and 1.2 g g/L at a modified pH of 9 36 .As shown in Fig. 8d, the MB dye gave the best results at 1 g/liter for 10CNT.In this study, we observed that an increased catalytic dose was responsible for the improved degradation efficiency because it provided additional reaction locations for the dye molecules 66 .This effect may be caused by the snooping of the radiation flowing into the reaction mixture, which is attributed to the upsurge in the catalyst dose 67 .This might also be due to the inflated quantity of hydroxyl and superoxide radicals produced by increasing the catalyst mass.Beyond the 1 g/L catalytic dose, no significant change in the photocatalytic dye degradation performance was observed.
Repeated use of the 10CNT catalysts was tested by accumulating the catalyst mass after the dye disintegration reaction was completed.The samples were cleaned and filtered multiple times using ethanol and DDW.To verify the reusability of the collected samples, they were dried and used again under the same experimental conditions.Thus the 10CNT sample sustained up to four cycles, showing 91%efficiency against MB dye even at the end of the fourth cycle.

Antifungal activity
In this study, we evaluated the antifungal activity of the phytopathogenic fungus Bipolaris sorokiniana, which causes spot blotch infections in wheat crops.Potato dextrose agar (PDA) is a regularly used medium for fungal culture, making it an appropriate substrate for testing the antifungal activity of catalysts.PDA is composed of potato infusion and dextrose, both of which supply nutrients for fungal development.The 5CNT, 10CNT, 15CNT, and 20CNT catalysts were added to the media at a specified concentration to test the antifungal activity.The medium was subsequently injected with fungal spores and fungal development was tracked over time.The antifungal activity of the substance under test is determined by the suppression of fungal growth, which manifests as a lack of apparent growth or a reduction in the number of fungal colonies.These findings suggest that Ag-loaded ZnO has substantial potential as a substitute for synthetic fungicides in the management of plant diseases 36 .The photo-induced generation of ROS and the poisoning effect due to Zn 2+ release are the two key contributors to the antifungal performance of ZnO nanoparticles.The mechanism of action of Ag-loaded ZnO:CNT against fungi involves the creation and accumulation of ROS and free radicals, which primarily disturb the cell wall, surface proteins, and nucleic acids of the fungi.In addition, they block proton pumps.This suggests that Agloaded ZnO:CNT has the potential to be an effective treatment for fungal infections 68 .The antifungal activity of Ag-loaded ZnO:CNT was evaluated using the poisoned food method, as shown in Fig. 9 69 .The diameter was measured using the Kirby-Bauer method, as shown in Eq. (12).where D c is the diameter of growth in the control plate and D s is the diameter of the plate containing Ag-loaded ZnO:CNT nanoparticles.The % antifungal activities of the 5CNT, 10CNT, 15CNT, and 20CNT were 48%, 46%, 43%, and 40%, respectively.

Antibacterial activity
The Ag-loaded ZnO:CNT composites were evaluated for their antimicrobial activity against Staphylococcus aureus (NCIM-2654), Bacillus cerius (NCIM-2703), Proteus vulgaris (NCIM-2813), and Salmonella typhimurium (NCIM-2501).The inoculum for microbial cultures was produced in sterile saline water.Bacterial growth was conducted on nutrient agar plates.Cultures of S. aureus, B. cerius, P. vulgaris, and S. typhimurium were spread out on a sterile nutrient agar plate.Sterile corkborers measuring 5 mm were used to create wells on these plates.Using a micropipette, 100 µg/ml of the synthesized substance was distributed in sterile dimethyl sulfoxide (DMSO).To evaluate antibacterial activity, the plates were incubated for 24 h at 370 °C.The antibacterial activity of the composite material was examined in conjunction with a blank dimethyl sulfoxide (DMSO) negative control.Using streptomycin as the reference medication, the antibacterial abilities of the composite materials were investigated using the agar well gel diffusion method.This study demonstrates the considerable antibacterial performance of the prepared composites because they curtail the growth of the given bacterial strains.Initially, DMSO medium was prepared using a liquid auger suspension.Bacterial strains were prepared separately for each sample and control, and the bacterial control suspensions were incubated for 12 h.at 37 °C70,71 .
The Ag-loaded ZnO:CNT composite samples were prepared at 2.5 mg/mL, and 10 µL drops of the sample were mixed with the above bacterial suspensions.Figure 10 shows the antibacterial activity of Ag-loaded ZnO:CNT catalysts against the bacterial strains, using streptomycin as a positive control and dimethyl sulfoxide (DMSO) and distilled water as a negative control.In the present study, the zone of inhibition (ZOI) values revealed that the 5CNT composite was more effective in constraining the development of the bacterial strain B. cerius, as the maximum ZOI was 21.66 ± 0.57 mm.The ZOIs of 5CNT composite against S. aureus, P. vulgaris, and S. typhimurium bacterial strains were 17.68 ± 0.57 mm 15.66 ± 0.57 mm, and 13.66 ± 0.57 mm, respectively, as illustrated in Table 3.The commercial drug streptomycin, which is exclusively effective against specific bacterial strains, was used to compare the outcomes.The ZOIs were 17.66 ± 0.57 mm, 25.66 ± 0.57 mm, 20.33 ± 0.57 mm, and 19.00 ± 1.00 mm for S. aureus, B. cerius, P. vulgaris, and S. typhimurium, respectively 72 .The aforementioned information shows the average ± standard error of three replicates (Table 3).

Conclusions
In this study, Ag-loaded ZnO:CNT nanocomposites were prepared using a refluxed chemical method.XRD analysis confirmed the structural clarity of the Ag-loaded ZnO:CNT nanocomposites.XRD investigation revealed the presence of silver and carbon peaks, and the average crystallite size ranged from 19 to 25 nm.The microstrain and dislocation density for Ag-loaded ZnO:CNT changed slightly with a change in the CNT content.The lattice parameters, crystal structure, and band gap energy of the Ag-loaded ZnO:CNT crystal structures for 5CNT, 10CNT, 15CNT, and 20CNT were found to be very similar.FE-SEM and EDS analyses confirmed the presence of Ag-loaded ZnO on the exterior of the CNT.The FESEM micrograph shows an agglomerated nano-flower-like morphology.The photocatalytic activities of MB and RB dyes were higher for the 10CNT.There was an increase in the photocatalytic efficiency with an increase in the pH of the dye solution up to the optimum value.The optimum result for MB dye was observed for 10CNT at pH 9, showing 100% photocatalytic efficiency in 2 min www.nature.com/scientificreports/ at a rate constant 1.48 min −1 .While The RB dye exhibited 99% photocatalytic efficiency in 20 min at pH 5 for 10CNT at a rate of 0.20 min −1 .The reuse of the 5CNT composite has shown excellent sustainability, it has shown 91% efficiency after 4th cycle.The variation in the MB dye concentration from 10 to 50 ppm revealed that the time required to degrade the dye solution increased with increasing dye concentration.In addition, we investigated the use of Ag-loaded ZnO:CNT as an antifungal agent against Bipolaris sorokiniana.It was observed that 5CNT showed better inhibition of Bipolaris sorokiniana fungus showing 48% efficiency.The 5CNT samples were tested against bacterial strains Staphylococcus aureus, Bacillus cerius, Proteus vulgaris, and Salmonella typhimurium and showed promising antibacterial activity in comparison with commercially available drugs.
In future research, we plan to incorporate advanced characterization techniques such as Electrochemical Impedance Spectroscopy (EIS) and Transmission Electron Microscopy (TEM) to gain deeper insights into the charge transfer dynamics and detailed structural properties of our silver stacked zinc oxide garnished on carbon  www.nature.com/scientificreports/nanotube composites.These analyses will complement our current Field Emission Scanning Electron Microscopy (FESEM) studies and provide a more comprehensive understanding of the materials' photocatalytic, antibacterial, and antifungal activities.

Figure 7 .
Figure 7. Graph of -Ln(C/C 0 ) versus irradiation time for 10 ppm (a) MB dye, (b) RB dye, and photocatalytic degradation efficiency against irradiation time for 10 ppm (c) MB dye (d) RB dye.

Figure 8 .
Figure 8. Photocatalytic degradation efficiency Vs. irradiation time of MB dye (a) at 30 ppm concentration (b) at 50 ppm concentration (c) pH variation (d) catalytic dose variation.

Table 1 .
Parameters calculated from XRD analysis.

Table 2 .
Photocatalytic degradation parameters of 5CNT, 10CNT, 15CNT, and 20CNT catalysts under visible light irradiation for as prepared 10 ppm MB and RB dyes.

Table 3 .
The zone of inhibition of bacterial strains S. aureus, B. cerius, P. vulgaris, and S. typhimurium.