Preparation and optimization photocatalytic activity of polymer-grafted Ag@AgO core-shell quantum dots

A novel method employing atmospheric pressure discharge plasma has been developed to reduce supported Ag nanoparticles (Ag NPs) and deposited on TiO 2 powder without the use of any environmentally and biologically hazardous reducing chemicals. Ag/TiO 2 nanocomposite was prepared by the atmospheric direct current plasma in water solution. Trisodium citrate and CMC was used as a capping agent for Ag nanoparticles. The nanocomposites were characterized using UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy. The results showed that Ag NPs with an average diameter of 20-35.5 nm were uniformly distributed on the powders surface. The presence of nanosilver particles in TiO 2 matrix is clearly visible. The bandgap of TiO 2 /Ag was confirmed (2.65-2.85 eV) through UV-vis DRS, which was lower than TiO2 (3.8 eV). The photocatalytic effect was conducted by methylene blue degradation test. The photocatalytic activity of a series of 2 wt. % Ag/TiO 2 composites was evaluated in the degradation of MB (used as a model pollutant) in aqueous solution under solar light. The 2.0 mol % of Ag-doped TiO 2 shows 96% degradation of methylene blue (MB) within 50 min under visible light irradiation and exhibit highest photocatalytic performance.

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“…04-0783). From the figure, it is clear that the silver present in TiO 2 catalyst is not as oxide (Mohammadi et al 2019).…”

Section: Resultsmentioning

confidence: 97%

Synthesis OF AG/TIO2 nanocomposite via plasma liquid interactions and degradation methylene blue

Скіба

Vorobyova

2020

Appl Nanosci

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“…50 The other peaks that appeared at 31.03, 55.08, and 73.47°are indexed to (110), (210), and (310) planes of AgO, respectively. 51 Figure 1b shows a broad diffraction peak at 23.28°corresponding to the amorphous SiO 2 (JCPDS no. 01-082-1554).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Collagen-Supported Amino-Functionalized Ag@SiO₂ Core–Shell Nanoparticles for Visible-Light-Driven Water Remediation

Subbiah

Thanikaivelan

2022

ACS Appl. Nano Mater.

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Environment-friendly, easily recoverable, cost-effective, visible-light-active, and biomass-derived photocatalysts for photocatalytic disinfection of wastewater are an indispensable priority to the growing scarcity of usable water resources. Herein, we synthesized a Ag@SiO2 core–shell (CS) nanosphere via chemical reduction and a modified Stöber method. Subsequently, a biodegradable nanocomposite was fabricated using CS nanospheres with dopamine (Do-Ag@SiO2) functionalization anchored with collagen (Coll-Do-Ag@SiO2), a renewable biomass sourced from biowaste, employing a sustainable and cost-effective method. The obtained Coll-Do-Ag@SiO2 nanocomposite displayed effective photocatalytic disinfection of tannery wastewater and Escherichia coli (E. coli), which was used as the representative microorganism with visible light irradiation. Complete photocatalytic disinfection was achieved within 15 and 20 min for E. coli and tannery wastewater, respectively, which is the fastest inactivation time reported so far. The process of annihilation of the cell wall and cell membrane was confirmed by field emission scanning electron microscopy images of bacteria acquired at different time intervals. The live/dead cell assay ascertains the loss of integrity of bacterial cell walls as the cause of death. Electron paramagnetic resonance spectroscopy and radical trapping studies reveal hydroxyl radicals (•OH), hyperoxide radicals (•O2 –), and photogenerated electrons (e–) as the main species in E. coli inactivation. The reactive species led to plasma membrane rupture, which was found to be the key factor in the destruction mechanism. The enhanced antibacterial performance of the Coll-Do-Ag@SiO2 nanocomposite was predominantly due to the improved photocatalysis due to stronger light absorption, a low band gap energy of 2.95 eV, and a low charge-transfer resistance (R ct) of 640 Ω. Considering the easy recovery and excellent photocatalytic performance, the biomass-derived visible-light-active Coll-Do-Ag@SiO2 nanocomposite is an attractive and inexpensive photocatalyst for water remediation applications.

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“…In works [23][24][25], information was presented that a silver nanoparticle core-shell structure can form at different synthesis conditions and capping agents. The band at max 410 nm can be assigned to the plasmon resonance of core-Ag 0 nanoparticles.…”

Section: Journal Of Nanomaterialsmentioning

confidence: 99%

Green Synthesis of Silver Nanoparticles in the Presence of Polysaccharide: Optimization and Characterization

Скіба

Vorobyova

Пивоваров

et al. 2020

Journal of Nanomaterials

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The process of obtaining aqueous solutions of silver nanoparticles with the use of a low-temperature nonequilibrium contact plasma and stabilizing agent—polysaccharide (sodium alginate)—has been examined. The synthesized Ag NPs were characterized by using UV-Vis spectroscopy, dynamic light scattering (DLS), scanning electron microscope (SEM), and XRD analysis. The effect of concentration of Ag+, sodium alginate, duration of processing by plasma discharge, and pH of liquid on the production of silver nanoparticles has been studied. The results demonstrated that synthesis provides the formation of silver nanoparticles for investigated concentrations of Ag+ (0.3-3.0 mmol/l) and 5.0 g/l Na-Alg (pH=7–10) within 1–5 minutes. From the SEM images, the silver nanoparticles are found to be almost spherical. Powder XRD results reveal that Ag nanoparticles have a face-centered cubic crystal structure. Zeta potential of plasma-chemically obtained colloidal solutions at various concentrations of Ag+ ions and stabilizing agent varies from −32.8 to −39.3 mV, indicating the moderate stability of synthesized nanoparticles.

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Preparation and optimization photocatalytic activity of polymer-grafted Ag@AgO core-shell quantum dots

Cited by 18 publications

References 27 publications

Synthesis OF AG/TIO2 nanocomposite via plasma liquid interactions and degradation methylene blue

Synthesis OF AG/TIO2 nanocomposite via plasma liquid interactions and degradation methylene blue

Collagen-Supported Amino-Functionalized Ag@SiO₂ Core–Shell Nanoparticles for Visible-Light-Driven Water Remediation

Green Synthesis of Silver Nanoparticles in the Presence of Polysaccharide: Optimization and Characterization

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Preparation and optimization photocatalytic activity of polymer-grafted Ag@AgO core-shell quantum dots

Cited by 18 publications

References 27 publications

Synthesis OF AG/TIO2 nanocomposite via plasma liquid interactions and degradation methylene blue

Synthesis OF AG/TIO2 nanocomposite via plasma liquid interactions and degradation methylene blue

Collagen-Supported Amino-Functionalized Ag@SiO2 Core–Shell Nanoparticles for Visible-Light-Driven Water Remediation

Green Synthesis of Silver Nanoparticles in the Presence of Polysaccharide: Optimization and Characterization

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Collagen-Supported Amino-Functionalized Ag@SiO₂ Core–Shell Nanoparticles for Visible-Light-Driven Water Remediation