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In this work, silver (Ag) doped zinc oxide (ZnO) nanoparticles were synthesized using zinc chloride, zinc nitrate, and zinc acetate precursors with (0 to 10) wt % Ag doping by a simple reflux chemical method. The nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet visibl...
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... The doping of Ag nanoparticles on ZnO enhanced the photocatalytic process by foiling the electron−hole pair recombination, and the process exhibited an excellent antibacterial potential even after the cutoff of the UV light. 15,16 On the global market, pudina has played a remarkable role as a medicine, diaphoretic, antiseptic, stomachic, antispasmodic, food flavoring, and spicing agent. 17,18 It is also used as medicine for cold, fever, flu, motion sickness, food poisoning, poor digestion, rheumatism, hiccups, stings, earaches, flatulence, sinusitis, and so forth. ...
... The peak at 400−600 cm −1 corresponds to Bi−O and Zn−O vibrational bands, and the peaks at 916 and 1123 cm −1 revealed the C−H vinyl and bending vibrations, respectively. 15,30 The FTIR peaks at 460 cm −1 indicated the Zr−O− Zr bond (deformation mode), with the peaks at 1002 and 1109 cm −1 corresponding to the stretching vibrations of the terminal Zr−O bond. 29−31 The FTIR bands at 1562 and 3530 cm −1 matched the −OH stretching and bending present in the adsorbed water molecule ( Figure 1a). ...
... In addition, the intensity of the peaks was increased by increasing the Ag concentration (from 1 to 9 mol % of Ag) (Figure 1b−f) due to agglomeration of Ag on the surface of the BZOP nanomaterial. 15,31 The pure BZOP and Ag-doped BZOP nanocomposite materials were analyzed by a high-resolution XRD technique, and the obtained XRD patterns are shown in Figure 2a−f. Figure 2a ascribes the XRD pattern of BZOP, which well matched with the standard δ-FCC structure of Bi 2 O 3 . ...
Novel visible-light-driven Ag (X)-doped Bi2Zr2O7 (BZO) nanocomposites in pudina (P) extract (Mentha spicata L.), X-1, 3, 5, 7, and 9 mol %, were synthesized by the one-pot greener solution combustion method. The as-synthesized nanocomposite materials were characterized by using various spectral [X-ray diffraction (XRD), Fourier transform infrared, UV–visible, UV– diffuse reflectance spectra, X-ray photoelectron spectroscopy], electrochemical (cyclic voltammetry, electrochemical impedance spectroscopy), and analytical (scanning electron microscopy–energy-dispersive X-ray spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller) techniques. The average particle size of the nanocomposite material was found to be between 14.8 and 39.2 nm by XRD. The well-characterized Ag-doped BZOP nanocomposite materials exhibited enhanced photocatalytic degradation activity toward hazardous dyes such as methylene blue (MB) and rose bengal (RB) under visible light irradiation ranges between 400 and 800 nm due to their low energy band gap. As a result, 7 mol % of Ag-doped BZOP nanocomposite material exhibited excellent photodegradation activity against MB (D.E. = 98.7%) and RB (D.E. = 99.3%) as compared to other Ag-doped BZOP nanocomposite materials and pure BZOP nanocomposite, respectively, due to enhanced semiconducting and optical behaviors, high binding energy, and mechanical and thermal stabilities. The Ag-doped BZOP nanocomposite material-based electrochemical sensor showed good sensing ability toward the determination of lead nitrate and dextrose with the lowest limit of detection (LOD) of 18 μM and 12 μM, respectively. Furthermore, as a result of the initial antibacterial screening study, the Ag-doped BZOP nanocomposite material was found to be more effective against Gram-negative bacteria (Escherichia coli) as compared to Gram-positive (Staphylococcus aureus) bacteria. The scavenger study reveals that radicals such as O2•– and •OH are responsible for MB and RB mineralization. TOC removal percentages were found to be 96.8 and 98.5% for MB and RB dyes, and experimental data reveal that the Ag-doped BZOP enhances the radical (O2•– and •OH) formation and MB and RB degradation under visible-light irradiation.
... The magnified diffraction patterns in Figure 1b clearly showed that, among Co-, Mn-, and Ag-doped ZnO, the AgZnO nanoparticles displayed the most peak broadening. The broadening of the diffraction peaks indicates a reduction in the crystalline size of ZnO upon substituting Zn 2+ with Co 2+ , Mn 2+ , and Ag + [46]. The larger size of the 4d metal cation Ag + (115 pm) compared to those of the 3d metal cations Co 2+ (74 pm) and Mn 2+ (83 pm) may have impaired the incorporation of Ag + into the Zn 2+ (74 pm) site in the crystal, resulting in the lattice distortion of the ZnO nanoparticles. ...
The construction of a heterojunction by coupling two semiconductor photocatalysts with appropriate band positions can effectively reduce the recombination of photogenerated charge carriers, thus improving their catalytic efficiency. Recently, ZnO photocatalysts have been highly sought after in the synthesis of semiconductor heterostructures due to their wide band gap and low conduction band position. Particularly, transition metal-doped ZnO nanoparticles are attractive due to the additional charge separation caused by temporary electron trapping by the dopant ions as well as the improved absorption of visible light. In this paper, we compare the effect of doping ZnO nanoparticles with 3d (Co and Mn) and 4d (Ag) transition metals on the structural and optical properties of ZnO/CdZnS heterostructures and their photocatalytic performance. With the help of scanning electron microscopy, the successful anchoring of doped and undoped ZnO nanoparticles onto CdZnS nanostructures was confirmed. Among the different heterostructures, Ag-doped ZnO/CdZnS exhibited the best visible-light-driven degradation of rhodamine B at a rate of 1.0 × 10−2 min−1. The photocurrent density analysis showed that AgZnO/CdZnS has the highest amount of photogenerated charges, leading to the highest photocatalytic performance. The reduction in the photocatalytic performance in the presence of hole scavengers and hydroxyl radical scavengers confirmed that the availability of photogenerated electrons and holes plays a pivotal role in the degradation of rhodamine B.
... Moreover, they aid in removing heavy metals from wastewater [9,25]. Researchers reported the use of AgNPs in composite and non-composite forms for pollutant degradation purposes [26,27]. Joseph et al. [28] reported the synthesis of AgNPs by a microwave irradiationassisted method using a new reducing agent namely hexamine in the presence of starch as stabilizing agent for the degradation osf methyl orange and rhodamine B. Also, single as well as mixed dye solutions were degraded using chemically synthesized AgNPs along with NaBH 4 [29]. ...
Dye wastewater released after improper treatment is extremely hazardous to the environment and all living things. As per the mandate, dye wastewater should be treated well in order to prevent any negative impacts after discharge. Herein, a single-step, rapid, and chemical-free radiation-induced approach for the synthesis of silver nanoparticles (AgNPs) was used to enhance the degradation of the Rose Bengal (RB) dye. X-ray diffraction (XRD) results showed the formation of a face-centered cubic structure of AgNPs synthesized at a gamma dose of 135 kGy. TEM image revealed the particle size around 11 nm and is in good agreement with the results of XRD and UV–Vis absorption spectroscopy. These AgNPs were examined for degradation study of RB dye. The RB dye was partially (~ 63%) degraded by bare gamma radiations at a dose of 2.7 kGy; however, synthesized AgNPs coupled with gamma radiations enhanced the degradation rate distinctly and ~ 95% degradation occurred. According to the findings of UV–Vis absorption spectroscopy, the RB dye was degraded and the degradation efficiency could be customized by gamma dose and concentration of AgNPs. The addition of AgNPs prior to gamma irradiation enhances the generation of hydroxyl radicals and the same results were validated by 3D-EEM fluorescence spectroscopy. The radiolytic degradation process of RB dye was found to obey the pseudo-first-order kinetics model. The values of dose constant (d) were determined as 0.0012 and 0.00041 Gy−1 for the cases with and without AgNPs, respectively. An increase in degradation rate indicates that the gamma radiation process coupled with the AgNPs is a promising alternative for potential RB dye degradation. This work provides a rapid and effective method for totally degrading textile effluents and has several applications in environmental remediation.
... ZnO is a popular photocatalyst for environmental remediation because of its low cost, large surface area, excellent electrochemical stability and high electron mobility [14][15][16][17]. However, its photocatalytic efficiency lags behind due to rapid recombination of photo-excited holes and electrons. ...
Nature is a perfect laboratory for creating novel nanomaterials for a variety of applications. A robust green synthesis approach to GO-loaded Ag/ZnO nanocomposite materials using medicinal plant extraction and their potential application in methyl orange dye degradation are reported. The straightforward technique employs zinc and silver nitrate precursors in an aqueous solution of medicinal plant extract, causing the precipitation process. Prior to photocatalytic investigations, the physico-chemical properties of the material are analysed using TG-DTA, XRD, FE-SEM, TEM, EDAX and BET. The developed material showcase hexagonal wurtzite structure of ZnO, with face-centered-cubic phase of Ag and AgCl. All the samples exhibit aggregated, irregular rounded grains, as expected in the precipitation synthesis process. Pristine ZnO showed 15.5% degradation efficiency towards methyl orange, which was further improved by doping Ag from 0.5 to 2 mol%. The catalyst with 1 mol% Ag doping resulted in the better photocatalytic activity (26.30%), which has again improved by loading the GO (27.46%). The outcome of this study provides the new insights to GO-loaded Ag/ZnO nanocomposites by green synthesis route, in view of photocatalytic applications.
... (d) Intensity peaks representing data for ZN-A, B, C, D, and E with black, red, blue, green, and peak curves respectively (where A, B, C, D, and E represents 0, 2, 5,7, and 10 wt% Ag doped ZnO respectively with ZN (zinc nitrate) precursor used). Reprinted with permission from ref. [78]; Copyright 2023, Omega. extracts were used by researchers to synthesize Ag-NPs, including Cassia auriculata, Pterocarpus santalinus, and Terminalia arjuna, among others [71,30,53]. ...
... In which 98% methylene blue was degraded, the degradation process of MB was continual for 5 cycles. In each recycling, just about 98-95% of MB was reduced with visible light irradiation, indicating no catalyst activity loss [78]. Ocimum tenuiflorum, Prosophis fracta, coffee seeds were also used to synthesize Ag-doped ZnO nanocomposites. ...
The world has been witnessing a rapid surge in environmental issues, and to combat this situation, researchers have been exploring the potential of nanomaterials-based solutions. Among these, photocatalytic nanomaterials (PNMs) and nanocomposites (NCs) synthesized using plant extracts have caught the recent attention of scientists. Our team was intrigued by this trend and sought to create an eco-friendly solution utilizing PNMs and NCs synthesized through plant extracts. Plants are a rich source of biomolecules that aid in the production of PNMs and their NCs for a diverse range of environmental applications. The resulting bio-synthesized PNMs/NCs are not only cost-effective and non-toxic, but also safe to handle and highly stable compared to other synthesis methods. While significant efforts have been made to create a greener and more affordable technology for the synthesis of PNMs/NCs, the challenge has been to extend the photocatalytic response to the visible light spectrum as opposed to just the UV spectrum, which represents only 6% of the total solar spectrum. Fortunately, the presence of special pigments in plant extracts facilitates the transport of electrons and holes, allowing for improved e − and h + transfer rates and charge carrier separations. The present review primarily focuses on the biosynthesized PNMs (Ag, MgO, and ZnO-based) and their NCs, examining their shape, size, and various antimicrobial and dye degradation applications. We also explore efficient green approaches for synthesis methods and compare them to pre-established physical and chemical processes. We hope that this review sheds light on the fundamental mechanisms behind photocatalyst interaction with bacteria and the basic synthesis and fabrication mechanisms for PNMs and NCs, ultimately leading to a better understanding and future research for the scientific community.
... Zinc oxide carbon nano tube composites samples were obtained by simple reflux method as reported earlier using zinc chloride, zinc nitrate and zinc acetate as precursor sources. [21] Each of 1M zinc precursor solutions were prepared in 100 ml double distilled water (DDW) by adding 10 ml diethylene glycol and stirring for additional 2 h at 80 °C. Subsequently, 10 mg of functionalized MWCNTs were sonicated for two hours in 10 mL of DDW and mixed with the zinc precursor solution. ...
... at 80 °C. [21] The prepared solution was allowed to cool overnight which appeared blackish brown in colour. The outcome of the reaction was washed and centrifuged multiple times with ethanol at 2000 rpm with drying at 70 °C for 36 hrs. ...
... The transformation of the aqueous phase into a stable network (secondary pollution) and the employment of multiple processes for purification, which is expensive and time-consuming, are two vital negative aspects of the procedures indicated [15]. Heterogeneous photocatalysis is among the several modern methods which widely used for the degradation of dyes [16]. In the process of photocatalysis, light energy is absorbed by a semiconducting material, which excites the electrons to move from the valence band to the conduction band. ...
... By analyzing photocatalytic degradation efficiency of all these samples against methylene blue (MB) dye under visible light, we have witnessed that 1.5 wt% copperdoped ZnO shows optimum results. Hence, 1.5C amalgamation with (i) CNT (labeled as CZC) along with (ii) silver (5 wt%) and CNTs (labeled as ACZC) for optimized sample was carried out by referring work of Snehal et al. [33]. For comparative studies, the photocatalytic degradation performance of these samples was performed against rose bengal (RB) and eosin yellow (EY) dyes. ...
... The sample with the highest catalytic performance (here in this case is 1.5 w% Cu-ZnO) was chosen for further co-doping. By referring the previous study done by Snehal et al. [33,35], 5 wt% silver nitrate was used to synthesize Ag-loaded Cu-ZnO:CNT. Here, 0.1 M zinc acetate solution was prepared in 150 ml of double distilled water; to this solution 1.5 Wt. % of copper acetate, 5 wt% of silver nitrate, and functionalized CNTs in specific quantity were added with continuous magnetic stirring at 60 °C for 2 h. ...
Here we report that photocatalytic and antioxidant properties of nanocomposite consist of silver- and copper-doped zinc oxide nanoparticles loaded onto carbon nanotubes (ZnO/Cu/Ag/CNT). The prepared nanocomposite material was analyzed using X-ray diffraction, scanning electron microscopy, tunneling electron microscopy, photoluminescence spectroscopy, and ultraviolet–visible spectroscopy for their structural, morphology, and optical studies. A photodegradation study was carried out against methylene blue, rose bengal, and eosin yellow dyes. The consequences of photocatalyst mass loading, pH, and dye concentration were explored. The optimum has result shown 99% degradation efficiency against methylene blue within 10 min of visible light irradiation at pH 10. A reusability test displayed the photocatalytic efficacy of the nanocomposite material was up to 83% after 4 rounds of use against methylene blue. The antioxidant performance of the nanocomposite material was studied against 2,2-diphenylpicrylhydrazyl. The results shown potential of the nanocomposite in photocatalytic and antioxidant activity giving quick, easy, and affordable alternative.
