Ag-ZnO Nanocomposites Research Articles

Synthesis and characterization of ZnO-Ag plasmonic nanocomposite: An efficient photocatalyst for the degradation industrial pollutant

In this work, a controlled synthesis method is presented for the synthesis of ZnO nanostructure and ZnO-Ag plasmonic nanocomposite. By following a single step low temperature hydrothermal method, two dimensional sheet like ZnO nanostructures and ZnO-Ag nanocomposites were obtained. The crystallinity and surface morphology of ZnO and ZnO-Ag nanocomposite is systematically characterized by powder X-ray diffraction, field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) and UV–visible spectroscopic studies. Thereafter the photo catalytic degradation of an industrial dye (Azure A chloride) has been demonstrated. Interestingly, it has been observed that in comparison to the bare ZnO plates, the ZnO-Ag nanocomposite catalyze the degradation process efficiently under illumination of visible light and about 98% degradation has been noticed even after 45 min of exposure. The presence of Ag nanoparticles in the composite found to reduce the band-gap of ZnO thereby improving the light absorption and consequently the degradation process. This method of catalyst preparation could be scaled up and will be a promising catalyst material for the sustainable future.

Fabrication, characterization and high photocatalytic activity of Ag-ZnO heterojunctions under UV-visible light.

Pure ZnO and Ag–ZnO nanocomposites were fabricated via a sol–gel route, and the obtained photocatalysts were characterized by XRD, SEM, TEM, BET, XPS, PL and DRS. The results showed that Ag0 nanoparticles deposit on the ZnO surface and Ag modification has negligible impact on the crystal structure, surface hydroxyl group content and surface area of ZnO. However, the recombination of photogenerated electrons and holes was suppressed effectively by Ag loading. The photocatalytic activity was investigated by evaluating the degradation of MB under xenon lamp irradiation as the UV-visible light source, and the results show that the photocatalytic activity of ZnO significantly improved after Ag modification. Ag–ZnO photocatalysts exhibit higher photocatalytic activity than commercial photocatalyst P25. The degradation degree of MB for 1%Ag–ZnO was 97.1% after 15 min. ˙O2− radicals are the main active species responsible for the photodegradation process, and Ag–ZnO heterojunctions generate more ˙O2− radicals, which is the primary reason for the improved photocatalytic performance.

Facile one-pot green synthesis of Ag\u2013ZnO Nanocomposites using potato peeland their Ag concentration dependent photocatalytic properties

Herein, a facile green synthesis route was reported for the synthesis of Ag–ZnO nanocomposites using potato residue by simple and cost effective combustion route and investigated the photocatalytic degradation of methylene blue (MB) dye. In the preparation potato extract functioned as a biogenic reducing as well as stabilizing agent for the reduction of Ag + , thus eliminating the need for conventional reducing/stabilizing agents. Ag–ZnO nanocomposites with different Ag mass fractions ranging from 2 to 10% were characterized by using XRD, FT-IR, XPS, SEM, TEM, and UV–Vis spectroscopy. XRD analysis revealed that the as prepared Ag–ZnO nanocomposites possessed high crystallinity with hexagonal wurtzite structure. TEM and SEM images showed that the Ag–ZnO nanocomposites in size ranging from 15 to 25 nm have been obtained, and the particle size was found to increase with the increase in percentage of Ag. FTIR results confirmed the characteristics band of ZnO along with the Ag bands. XPS analysis revealed a pair of doublet with peaks corresponding to Ag and a singlet with peaks corresponding to ZnO. With the increase of concentration of Ag in ZnO, the intensity of NBE emission in the PL spectra was observed to be decrease, resulted to the high photocatalytic activity. Photocatalytic properties of Ag–ZnO nanocomposites evaluated against the MB dye under visible-light irradiation showed superior photodegradation of ~ 96% within 80 min for 2% Ag–ZnO nanocomposites. The apparent reaction rate constant for 2% Ag–ZnO nanocomposites was higher than that of other nanocomposites, which proved to be the best photocatalyst for the maximum degradation of MB. Furthermore, various functional parameters such as dosing, reaction medium, concentration variation were performed on it for better understanding. The enhancement in photocatalytic degradation might be due to the presence of Ag nanoparticles on the surface of ZnO by minimizing the recombination of photo induced charge carriers in the nanocomposites.

A New Nano-Platform of Erythromycin Combined with Ag Nano-Particle ZnO Nano-Structure against Methicillin-Resistant Staphylococcus aureus.

Nano-particles have been combined with antibiotics in recent studies to overcome multidrug-resistant bacteria. Here, we synthesized a nano-material in which Ag nano-particles were assembled with a ZnO nano-structure to form an Ag-ZnO (AZO) nano-composite at low temperature. This material was combined with erythromycin (Ery), an antibiotic effective towards gram-positive bacteria, using three different approaches (AZO + Ery (AZE) [centrifuged (AZE1), used separately after 1-h gap (AZE2), without centrifugation (AZE3)]) to prepare a nano-antibiotic against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA). X-ray diffraction analysis and transmission electron microscopy confirmed the presence of Ag nano-particles and ZnO nano-structure. The elemental and chemical state of the elements present in the AZO nano-composite were assessed by X-ray photoelectron spectroscopy. The antibacterial activity of AZE samples against both Escherichia coli and S. aureus strains including MRSA was evaluated in antibacterial and morphological analyses. The AZE3 sample showed greater antibacterial activity than the other samples and was comparable to erythromycin. AZE3 was ~20-fold less prone to developing bacterial resistance following multiple exposures to bacteria compared to erythromycin alone. The AZE3 nano-composite showed good biocompatibility with 293 human embryonic kidney cells. Our newly synthesized nano-platform antibiotics may be useful against multidrug-resistant gram-positive bacteria.

Green Microwave-assisted Synthesis of ZnO-Ag Nanocomposite using Clove Oil (Syzygium aromaticum L.) and Its Bioactivity against Staphylococcus aureus

Microwave-assisted synthesis of zinc oxide-silver (ZnO-Ag) nanocomposite using clove (Syzygium aromaticum L.) oil has been investigated. Variation of solvents and irradiation time of microwave was studied. The product characterization was carried out using XRD, FT-IR, and SEM-EDS. The XRD analysis indicates ZnO-Ag nanocomposite has a polycrystalline structure. The ZnO peak was detected at 2θ = 31.99; 34.58 and 68.05, whereas the Ag peak was detected at 2θ = 38.36 and 44.49. The increasing of irradiation time reduces the crystallite size, and generally has size range between 9 and 12 nm. SEM-EDS confirmed the existence of the ZnO-Ag nanocomposite with percentage of Zn (46.89%), O (29.72%) and Ag (23.39%). Moreover, antibacterial evaluation on Staphylococcus aureus give the inhibition zone in 13.3 mm. This result slightly gives better activity than the reference.

Enhanced photocatalytic properties of CuO–ZnO nanocomposites by decoration with Ag nanoparticles

Rational design of multi-component heterostructure photocatalyst is capable of combining the advantages of the different components. Here, a ternary CuO–ZnO–Ag nano-composite was fabricated by a facile sol-gel method for the photodegradation of organic dye pollutants in wastewater. Decorating Ag NPs on the surfaces of CuO–ZnO nanocomposites improves their photocatalytic activities, which can be further enhanced by tuning the Ag loading level. At 2 mol%, the photocatalytic degradation efficiencies of CuO–ZnO nanocomposites for methylene blue (MB), methyl orange (MO), rhodamine b (RhB) under simulated sunlight irradiation, and for MB under visible light irradiation are increased by 42%, 42%, 63% and 78%, respectively. The enhanced efficiencies can be attributed to the strengthened visible light absorption and the lower recombination rate of photogenerated electron-hole pairs. This work will trigger an inspiration for lowering the dosage of noble metal in photocatalyst by building the simple multiheterostructure consisting of the low-cost metal elements.

Green synthesis of Ag-ZnO nanocomposites using Trigonella foenum-graecum leaf extract and their antibacterial, antifungal, antioxidant and photocatalytic properties.

In the present study, biological synthesis of Ag-ZnO nanocomposites was performed using hydroalcoholic extract of fenugreek leaves. Metal/semiconductor oxide nanocomposites are excellent owing to their optical, electrical, magnetic, and chemical properties that are not detected in single individual constituents. The synthesized Ag-ZnO nanocomposites were investigated through the use of methods such as FTIR, UV vis DRS, SEM-EDX, TEM, XRD, zeta potential analysis, and DLS. The synthesized Ag-ZnO nanocomposites had an average particle size of about 75nm and a zeta potential of -37.5mV. The XRD results confirmed that Ag was successfully introduced into the Ag-ZnO nanocomposites via a hydrothermal method. The antimicrobial and antifungal activities of Ag-ZnO nanocomposites were evaluated by agar well diffusion method against three microbial and fungal strains; it was found that the Ag-ZnO nanocomposites were toxic against all the tested microbial and fungal strains. Ag-ZnO nanocomposites was observed to have significant antioxidant activity against DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals. The Ag-ZnO nanocomposites exhibited excellent photocatalytic activity and stability against the degradation of malachite green under visible light irradiation. The study successfully applied a simple and eco-friendly method for synthesizing efficient multifunctional Ag-ZnO nanocomposites using green synthetic approach.

Synthesis of ZnO-Ag Nanocomposites trough Ultrasonication-Microwave Combination Method with Clove Leaf Oil

ZnO and Ag nanoparticle have known their antibacterial activity especially their use in medical materials. In this study, ZnO-Ag Nanocomposite was synthesized by ultrasonication-microwave combination method with variation of reaction time using clove oil as their bioreductor. ZnO-Ag was prepared from ZnO Acetate as a source of ZnO and AgNO3 as a source of Ag. The crystallinity structure, average particle size, morphology, and composition of ZnO-Ag was characterized by X-Ray Diffraction, Scanning Electron Microscope, and Energy Dispersive X-ray Spectroscopy. X-ray diffraction pattern indicates that reaction time of 30 minutes have optimal synthesis results. The nanocomposite obtained consists of 43.2 % Ag nanoparticle, 17.5 % hexagonal Zincite, 14.6% Zinc Oxide, 14.5% wulfingite (deuterated), and 10.2% Zn(OH)2 with average particle size of 28.29 nm according to Scherer’s equation. The result of scanning electron microscope showed that ZnO has an fiber shape and Ag has a round shape.

The effect of catalyst weight on the photocatalytic performance of ZnO-Ag nanocomposites prepared by flame pyrolysis method

ZnO is the most widely used as a catalyst material for photocatalytic application due to the suitable band gap energy and the chemical stability. It was reported by our previous study that the photocatalytic performance was significantly affected by the Ag content. In this study, ZnO-Ag nanocomposite materials have been successfully fabricated by flame pyrolysis and the effects of catalyst weight ranging from 2 to 10 mg on the photocatalytic performance were also investigated. Zinc acetate and silver nitrate were used as precursors for producing ZnO-Ag nanocomposites. The catalyst products, ZnO-Ag nanocomposite, were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). While, UV Vis spectrometry was used to measure the concentration of methylene blue (MB) before and after irradiations. Photocatalytic performances of nanocomposites were performed by evaluating the degradation of MB under UV and sunlight irradiations. The photocatalytic tests showed that the best performance was attained when the Ag content was 5 wt% and the weight of catalyst was as much as 10 mg after irradiation with sunlight, where the degradation rate of MB was 98% and the rate constant was 0.09/min.

Smart Fortified PHBV-CS Biopolymer with ZnO-Ag Nanocomposites for Enhanced Shelf Life of Food Packaging.

Thymus vulgaris leaf extract was used as a stabilizer and reducing agent in the green, facile, and biomimetic hydrothermal decomposition reaction for the fabrication of zinc oxide-silver nanocomposites (ZnO-Ag NCs). The nanocomposite (NC) as an active agent was integrated into poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-chitosan (PHBV-CS) in a highly precise ratio of solvent mixture by ultrasonication without the aid of any coupling agent to fabricate the novel degradable biopolymer (BP) nanocomposite via solvent casting method to enhance the mechanical properties and antimicrobial activity and with the lowest immigration rate to improve the shelf life of poultry items. The ZnO-Ag NCs as a nanoactive agent in the food packaging preserved food safety by controlling its spoilage. The morphology, physical, mechanical, barrier, antibacterial, and migration properties of the nanocrystals were assessed via several characterization methods to show the enhancement of the prepared polymer in various aspects of properties. The NCs BP were used for potential sensory evaluation of chicken breast refrigerated over a period of 15 days. The data demonstrated that these bio-based nanocomposites show great antimicrobial activity that offers perspectives for the replacement of traditional petrochemical-based polymers currently used for food packaging of poultry items.

Enhanced bioactivity of Pure ZnO and ZnO-Ag nanocomposite Using Sol-Gel method for Self-Cleaning Application

In the current study, Pure ZnO and Ag-ZnO nanocomposite are established using the sol-gel method with the influence of ammonia solution NH4OH to incorporate Ag ions into ZnO and form Ag-ZnO nanocomposites. Then pure ZnO and Ag-ZnO nanocomposites were annealed at 450oC for tow h in a muffle furaning using temperture controlling, and heat rate was set at temperature 100oC per min. The structural and morphological properties of samples were characterized using XRD, FTIR, and FESEM with Energy dispersive X-rays (EDX). In addition, the antibacterial activity of pure ZnO and Ag- ZnO nanocomposite was evaluated against gram-positive and gram-negative organisms by plate count test. The results of the test revealed strong antibacterial behavior of nanocomposite against bacteria as compared to pure ZnO and improved efficiency of incorporation Ag ion on ZnO.

Biosynthesis, Characterization and Structural Properties of a Novel Kind of Ag/ZnO Nanocomposites In Order to Increase Its Biocompatibility Across Human A549 Cell Line

Recently, Ag/ZnO nanocomposite (Ag/ZnONC) has been known as one of effective antimicrobial agents. However, its interesting aspects could cause several health effects. This problem can be rectified by capping its surface via the addition of a biomolecule which form a “bio-capped layer” around the particles and prevent them from interacting human cells. In this study, a new fabrication of bio-capped Ag/ZnONCs in various amounts of silver has been reported. Stable and spherical bio-capped Ag/ZnONCs were produced using extract which acts as a reducing and capping agent. The physicochemical, properties of the fabricated NCs was characterized by UV-Vis, XRD, DLS, zeta potential, SEM, XRD, EDX, and FTIR, antioxidant activity. In addition, the mechanism of fabrication has been suggested. Our method of fabrication could be an eco-friendly technique and considered as an alternative to other techniques such as electro- and photo-chemical, chemical, and physical techniques. Our results show that the as-synthesized Ag/ZnONCs possess antioxidant activity and the secondary metabolites of the extract adsorbed on the NC reacts with DPPH. Moreover, the cytotoxicity of bio-capped Ag/ZnONCs (0.15% of Ag) to treat cell lines was evaluated by using cell viability test of human A549 cell line. The obtained results demonstrated that concentrations of up to 0.1 mg/mL of bio-capped Ag/ZnONCs induced no significant harmful to the cells. Hence, the present study proved that the fabricated NCs have the potential to use in industrial and pharmacological applications.

Designed synthesis of microstructure and defect-controlled Cu-doped ZnO–Ag nanoparticles: exploring high-efficiency sunlight-driven photocatalysts

Cu-doped ZnO nanoparticles composited with Ag were synthesized by a one-step sol-gel method in this work, aiming at highly photocatalytic activity and possible application under sunlight (especially near ultraviolet and visible light regions, 300–760 nm) irradiation. Scanning electron microscopy (SEM) shows that the introduction of Cu inhibits particle aggregation. X-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) reveal that Zn(Cu)O–Ag nanoparticles (CZA NPs) are composed of metallic Ag (Ag0) and Zn(Cu)O nanocrystals; while at the Cu concentration of higher than 2%, a few CuO nanocrystals appear. Transmission electron microscopy (TEM) results evidenced the well-defined formation of Zn(Cu)O–Ag and/or CuO–ZnO–Ag heterojunctions. UV–vis spectra display that the visible absorption of the samples is obviously enhanced after the Cu introduction. At a low Cu doping level (0.2%) and moderate Cu concentration (3%–5%), the blue and green photoluminescence (PL) emission strength of the samples becomes very weak in comparison to other samples, indicative of the high separation of photogenerated electron-hole pairs. Reasonably, the higher photocatalytic degradation (complete degradation of methylene blue (MB) and methyl orange (MO) within 40 min under the simulated sunlight irradiation) are achieved in these cases: low Cu doping level (0.2%) and moderate Cu concentration (3%–5%) in CZA NPs. Further, we checked the effects of other factors on the photocatalytic degradation for possible application. Our results suggest that one well-designed composite type such as element-doped Zn(M)O–Ag nano-heterojunction or complicated metal oxide–ZnO–Ag nanocomposites possessing suitable band structures for the separation and utilization of photo-generated carriers, will remarkably improve the photocatalytic performance of nano-ZnO under sunlight irradiation.

Enhancement of the PSF/PVP membrane performance by Ag-ZnO incorporation

In this work, bare and Ag-ZnO nanocomposite incorporated Polysulfone (PSF)/Polyvinyl pyrrolidone (PVP) membranes were fabricated by phase inversion method. Different concentrations of Ag-ZnO nanocomposites (0.5 wt%, 1 wt% and 2 wt%) were incorporated into PSF/PVP blend to enhance the performances of the membranes in terms of water permeability, antimicrobial activity and sulphate rejection. FE-SEM images show that the addition of Ag-ZnO into membrane caused significant changes in porous morphologies. The AFM images revealed that the surface roughness was increased by Ag-ZnO incorporation. Further, the membranes were characterised by contact angle measurement, tensile test measurement and TGA analysis. These results proved that the Ag-ZnO incorporated membranes were more hydrophilicity, enhanced mechanical and thermal properties compared to that of bare membrane. It has been assessed that 1 wt% Ag-ZnO incorporated membrane showed better performance as it possess high hydrophilic nature, salt removal capability and antimicrobial activity though 2 wt% Ag-ZnO membrane showed high water permeability.

Antifouling Properties of Silver-Zinc Oxide Polyamide Thin Film Composite Membrane and Rejection of 2-Chlorophenol and 2,4-Dichlorophenol.

The silver-zinc oxide (Ag-ZnO) polyamide thin film composite (PA-TFC) membrane was prepared by interfacial polymerization. The Ag-ZnO/PA-TFC membrane was characterized by attenuated total reflectance fourier-transform infrared spectroscopy (ATR-FTIR) for polyamide functional groups and contact angle for surface hydrophilicity. The Ag-ZnO/PA-TFC membrane was further characterized by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) for morphology and surface roughness, respectively. The performance of the fabricated membrane was investigated using pure water flux, permeability, rejection, flux recovery, and fouling resistance using low molecular weight organic pollutants, 2-chlorophenol (2-CP) and 2,4-dichlorophenol (2,4-DCP). The results were compared to the neat (PA-TFC) membrane. It was observed that incorporation of Ag-ZnO nanocomposites into the PA-TFC membrane improved hydrophilicity, permeation, rejection, and fouling resistance properties of the membrane. The contact angle decreased from 62.8° to 54° for PA-TFC and the Ag-ZnO/PA-TFC membrane, respectively. The presence of Ag-ZnO enhanced permeability of the membrane from 0.9 (Lm−2h−1bar−1) to 1.9 (Lm−2h−1bar−1). Modification of the membrane with Ag-ZnO further showed an enhanced rejection of 2-CP and 2,4-DCP from 43% to 80% and 58% to 85%, respectively. The 2,4-DCP molecules were rejected more than 2-CP due to enhanced repulsive forces from the extra Cl ion. A high flux recovery of about 95% was achieved for the modified membrane compared to 64% for the neat membrane. The improved flux recovery was an indication of enhanced antifouling propensity.

Ultrasound assisted preparation and characterization of Ag supported on ZnO nanoparticles for visible light degradation of methylene blue dye

The present work reports sonochemical preparation of zinc oxide (ZnO) and silver decorated ZnO (9wt%) with the use of zinc acetate, silver nitrate and sodium carbonate as precursors in 60min duration. The resulted ZnO and silver decorated ZnO nanoparticles were characterized with SEM, FE-SEM, FTIR, XRD and UV–Vis techniques. XRD analysis reveals hexagonal quartzite crystalline phase of ZnO with highest purity. The doping of silver differs the ionic radii of the elements and that produces the strain in Ag-ZnO nanocomposites. The average crystallite size of ZnO and Ag-ZnO estimated to be 17.53 and 18.73nm, respectively with the use of XRD analysis. The lattice parameters, crystallite size and unit cell volume was observed to be increased with the loading of Ag on ZnO nanoparticles during its preparation with the aid of ultrasonic irradiations. The observed lesser size of nanoparticles and nanocomposites is due to the use of ultrasonic irradiations. Photocatalytic properties of ZnO and Ag-ZnO (doped) nanocomposite was examined for the degradation of methylene blue (MB) dye in aqueous solution under solar light irradiations. Influence of the initial dye concentration, catalyst loading, pH, and temperature on the degradation of MB dye was investigated and optimized conditions were obtained. Furthermore, a relative study of photocatalytic properties of ZnO and Silver doped ZnO nanocomposites prepared by conventional and sonication method was accomplished and the results were discussed. A maximum degradation of MB dyes was achieved (~96.2%) under optimized conditions for Ag doped ZnO nanocomposite prepared by ultrasound assisted method.

Novel Green Biomimetic Approach for Synthesis of ZnO-Ag Nanocomposite; Antimicrobial Activity against Food-borne Pathogen, Biocompatibility and Solar Photocatalysis

A simple, eco-friendly, and biomimetic approach using Thymus vulgaris (T. vulgaris) leaf extract was developed for the formation of ZnO-Ag nanocomposites (NCs) without employing any stabilizer and a chemical surfactant. T. vulgaris leaf extract was used for the first time, in a novel approach, for green fabrication of ZnO-Ag NCs as a size based reducing agent via the hydrothermal method in a single step. Presence of phenols in T. vulgaris leaf extract has served as both reducing and capping agents that play a critical role in the production of ZnO-Ag NCs. The effect of silver nitrate concentration in the formation of ZnO-Ag NCs was studied. The in-vitro Antimicrobial activity of NCs displayed high antimicrobial potency on selective gram negative and positive foodborne pathogens. Antioxidant activity of ZnO-Ag NCs was evaluated via (2,2-diphenyl-1-picrylhydrazyl) DPPH method. Photocatalytic performance of ZnO-Ag NCs was appraised by degradation of phenol under natural sunlight, which exhibited efficient photocatalytic activity on phenol. Cytotoxicity of the NCs was evaluated using the haemolysis assay. Results of this study reveal that T. vulgaris leaf extract, containing phytochemicals, possess reducing property for ZnO-Ag NCs fabrication and the obtained ZnO-Ag NCs could be employed effectively for biological applications in food science. Therefore, the present study offers a promising way to achieve high-efficiency photocatalysis based on the hybrid structure of semiconductor/metal.

Synthesis of nanostructured ZnO, AgZnO and the composites with reduced graphene oxide (rGO-AgZnO) using leaf extract of Stigmaphyllon ovatum

A green method is reported for the synthesis of reduced graphene oxide (rGO), zinc oxide nanoparticles (ZnO), AgZnO and rGOAgZnO nanocomposites. The optical properties of the as-synthesized nanomaterials showed bands around 370 nm for ZnO, which red shifted for the nanocomposites with additional band ascribed to the surface plasmon band of Ag around 410–420 nm. The band gap energies were obtained as 3.95, 3.15, 2.45 and 2.75 eV for the rGO, ZnO, AgZnO and rGOAgZnO respectively. The photolumniscent (PL) measurement, at excitation wavelength of 320 nm, showed about four emission peaks for the ZnO nanoparticles with some differences in the spectra of the composites due to reduced surface defects as a result of Stern-Volmer quenching. The photocatalytic studies measured over 120 min reaction time using methlyene blue, showed that the nanomaterials were effective photocatalysts with efficiency of 68.1, 62.7, 61.7 and 57.4% for the rGOAgZnO, ZnO, rGO, and AgZnO respectively.

Tea-phytochemicals functionalized Ag modified ZnO nanocomposites for visible light driven photocatalytic removal of organic water pollutants

Biogenic synthesis of semiconductor nanoparticles (NPs) as well as metal-semiconductor nanocomposites (NCs) has become a subject of comprehensive interest and research due to its cost-effective and eco-friendly synthesis approach. In this regard, the current work focuses on the biosynthesis of Zinc oxide (ZnO) NPs and Silver-Zinc oxide (Ag-ZnO) NCs using the leaves extract of tea plant (Camellia sinensis). The as-synthesized samples were characterized by various optical, structural and elemental characterization techniques. The successful capping of tea-phytochemicals were confirmed from the bonding information through Fourier Transform Infrared Spectroscopic analysis, while the formation of ZnO NPs and Ag-ZnO NCs were established using x-ray Diffraction, Energy Dispersive x-ray and x-ray photoelectron spectroscopic techniques. Optical absorbance of ZnO NPs revealed the formation of smaller particle size (∼5.2 nm) as compared to bulk ZnO, while the absorbance of Ag-ZnO NCs depicted the presence of metallic Ag in the sample through surface plasmon resonance. The potential of as-synthesized samples were then tested through the photocatalytic and catalytic degradation of organic water pollutants, such as Methylene blue, Paracetamol drug and para-Nitro phenol. The results indicated that Ag deposition on ZnO nanostructure was beneficial in terms of both catalytic as well as photocatalytic degradation under dark condition and visible light irradiation, respectively. A commercially available light source was used for photodegradation process instead of solar irradiation. In addition, an attempt has also been made to explain the plausible pathway of Ag-ZnO NCs formation by the functionalization of tea-phytochemicals. To the best of Authors’ understanding, this is the first attempt so-far reporting a cost-effective biosynthesis process of Ag-ZnO NCs using tea-extracts and its photocatalytic activity under visible light for the degradation of common organic pollutants.

Photocatalytic Activity of ZnO-Ag Nanocomposites Prepared by a One-step Process using Flame Pyrolysis

Photocatalytic Activity of ZnO-Ag Nanocomposites Prepared by a One-step Process using Flame Pyrolysis