Decoration Of Nanoparticles Research Articles

Decoration of X2C nanoparticles on CdS nanostructures for highly efficient photocatalytic wastewater treatment under visible light

It is necessary to design and fabricate effective and stable heterostructures to enhance the photocatalyst performance. In this research, we developed stable metal carbide (Mo2C and W2C) embedded cadmium sulfide (CdS) hybrid nanostructure photocatalysts to increase the light adsorption capacity and effectively enhance the photocatalytic activity.A simple hydrothermal technique was employed to effectively fabricate the CdS and CdS:X2C (X = Mo or W) hybrid photocatalyst. Microscopy studies demonstrated the surface modification of the hybrid structure due to the X2C incorporation with CdS. X-ray photoelectron spectroscopy, X-ray diffraction, and energy dispersive analysis measurements were performed to characterize the hybrid structure materialization. The photocatalytic properties of CdS and CdS:X2C hybrid structures were evaluated by degrading Rhodamine B (RhB) under visible light. The polygonal shaped CdS:X2Cexhibited excellent photocatalytic activities. The highly porous structure of CdS:X2C indicated that manyexposed active facets were available due to the embedding of petal-shaped X2C, which enabled the effective adsorption and transference of RhB organic molecules to the active edges. Moreover, the hierarchical structure of CdS:X2Ccorresponded to a high light-absorption efficiency due to the increased length of light trails and enhanced interfacial shifting of the valence state electrons, which reduced the optical band-gap.

Simultaneous visible and ultraviolet photoresponse improvement of MoS2/ZnO heterostructure photodetector via direct resonant coupling of Au nanoparticles localized surface plasmon resonance

Localized surface plasmon resonance (LSPR) as a unique property of metal nanoparticles (NPs) has been widely applied to enhance the performance of optoelectronic devices. However, limited by the specific resonance frequency of plasmonic NPs, the LSPR of NPs can only improve the photoresponse performance of photodetectors at specific wavelength. In this work, a simple strategy is proposed to simultaneously improve the performance of the p-MoS2/n-ZnO heterostructure photodetector in visible and ultraviolet (UV) light regions by modifying Au NPs. The Ilight/Idark ratio of the photodetector is considerably increased after the functionalization with plasmonic Au NPs under visible and UV light illumination due to the direct resonant coupling of LSPR. In particular, the photocurrent of the photodetector increases 14.8 times after Au NPs modification under 532 nm illumination, giving rise to an obvious increase in responsivity, external quantum efficiency and specific detectivity. Moreover, the modification of Au NPs facilitates the rapid separation of electrons and holes due to the generation of surface depletion regions located at Au/MoS2 and Au/ZnO interfaces. Consequently, the photoresponse speed is also drastically improved after Au NPs decoration in both visible and ultraviolet light regions. The strategy of direct resonant coupling of Au NPs LSPR with two photosensitive materials proposed in this work will provide a new avenue for optimizing the performance of optoelectronic devices.

Gold nanoparticle decoration of metal oxides (M = Cu, Ni, Zn) embedded in porous MOF-derived: Facile synthesis and possible applications

Gold nanoparticle decoration of metal oxides (M = Cu, Ni, Zn) embedded in porous MOF-derived: Facile synthesis and possible applications

Copper-Based Nanocatalysts with SiO2 and Carbon Dual-Layer Coatings and Metallic Ni/CuNi Decoration toward Highly Efficient Nitroaromatics Reduction.

Nanocomposites with novel architectures and multifunctional properties have attracted extensive attention among related researchers. Herein, we develop a magnetically responsive Ni/CuNi nanoparticle (NP) decoration of Cu-based composites that could serve as recoverable nanocatalysts for nitroaromatics reduction. The nanocatalysts consist of an inner copper core and abundant tiny satellite Ni/CuNi NPs, which are tightly combined as a stable whole part by a silica interlayer and a carbon outer layer. In addition to the high catalytic activity, the outer Ni/CuNi NPs exhibit a strong magnetic response toward the external magnetic field, thereby offering a convenient way to separate the composites from the reaction solution. Moreover, characterization results reveal that high annealing temperature (above 700 °C) favors the construction of yolk-shell nanostructures and the formation of outer bimetallic CuNi NPs. As a result, owing to the excellent catalytic performance of the Cu inner cores, the high coverage of outer Ni or CuNi NPs, and the unique sandwich-like structure, the resultant Cu@SiO2@C-Ni composites show the use of such magnetically responsive recoverable nanocatalysts for the 4-nitrophenol reduction. Hence, this research could provide new guidelines for designing and synthesizing novel and efficient copper-based composites for other fields, such as carbon dioxide reduction, energy storage, and batteries.

Synthesis and design of spinel ZnAl2O4 nanowires with PtO nanoparticles decoration for enhanced induced visible light Hg(II) reduction

Synthesis and design of spinel ZnAl2O4 nanowires with PtO nanoparticles decoration for enhanced induced visible light Hg(II) reduction

Zwitterionic choline phosphate conjugated folate-poly (ethylene glycol): a general decoration of erythrocyte membrane-coated nanoparticles for enhanced tumor-targeting drug delivery

Erythrocyte membrane nanosystems have become one of the important research directions of disease treatment, especially for tumor treatment, and can enhance the long circulation time of anti-cancer drugs in vivo, and penetrate and accumulate in the tumor site effectively. However, erythrocyte membranes lack targeting properties and it is necessary to provide tumor-targeting function by modifying erythrocyte membranes. In this study, we report on a novel modification method of an erythrocyte membrane nanosystem to target tumors. Specifically, the tumor-targeting molecule folate-poly (ethylene glycol) (FA-PEG) was modified with a zwitterionic 2-(methyl acryloyoxy) ethyl choline phosphate (MCP) by the Michael addition reaction to obtain MCP-modified FA-PEG (MCP-PEG-FA). Based on the strong "N-P" tetravalent electrostatic interaction between MCP and phosphatidyl choline on the erythrocyte membranes, MCP-PEG-FA can be modified on the erythrocyte membrane encapsulated doxorubicin (DOX) loaded poly(lactic-co-glycolic acid) (PLGA) nanosystem to form a tumor-targeting erythrocyte membrane nanosystem (FA-RBC@PLGA-DOX). The results show that MCP-PEG-FA was synthesized and successfully bonded to the erythrocyte membrane nanosystem, and the FA-RBC@PLGA-DOX nanosystem had a better tumor-targeting function and tumor killing effect compared with those of the nanosystems without FA ligand modification. The universal modification method of erythrocyte membranes is successfully provided and can be applied to the treatment of various diseases.

Polydopamine-assisted decoration of Se nanoparticles on curcumin-incorporated nanofiber matrices for localized synergistic tumor-wound therapy.

The management of surgical wounds incurred during tumor removal procedures has become a non-negligible issue. Herein, for the first time, an implantable polymer-based nanofiber matrix is developed for postoperative tumor management by promoting wound healing and preventing cancer recurrence. The multifunctional matrix is successfully prepared by assembling chitosan-stabilized Se nanoparticles (SeNPs) at the surface of polydopamine (PDA) modified poly(ε-caprolactone)/curcumin fibres (PCL/CUR), denoted as PCL/CUR/PDA@Se. In this system, PDA as functionalized layers coated onto the PCL/CUR surface favors the effective immobilization of SeNPs through a covalent bond, as well as acts as a gatekeeper guaranteeing the sustained release of CUR. The CUR/SeNPs present excellent antitumor efficacy, respectively, which supports the nanocomposite matrix to efficiently kill cancer cells in vitro by inducing mitochondrial dysfunction caused by the ROS overproduction, and significantly suppressing the tumor growth in vivo. Additionally, due to the synergistic antioxidant activity of CUR and SeNPs, the nanofibrous matrix distinctly facilitates the adhesion and proliferation of normal fibroblast cells, and simultaneously accelerates wound healing during tumor treatments in tumor-bearing mice. These results suggest that the PCL/CUR/PDA@Se matrix with bifunctional properties is a promising candidate for local tumor-wound therapy. This work offers an innovative strategy to develop new improved post-surgery therapies for cancer patients.

Bio-surfactant mediated synthesis of Au/g-C3N4 plasmonic hybrid nanocomposite for enhanced photocatalytic reduction of mono-nitrophenols

A bio-surfactant assisted synthesis route has demonstrated in room temperature for decoration of gold nanoparticles (AuNPs) on g-C3N4 using Averrhoa carambola leaf extract towards mono-nitrophenol reduction under visible light irradiation. Biomolecules of the leaf extract and optimised reaction condition played a vital role on tuning the morphology and optoelectronic properties of AuNPs. The size of AuNPs were found to be 15 ± 3 nm on 2D g-C3N4 sheets by TEM and STEM-HAADF analysis. Among the designed plasmonic hybrid photocatalysts 3-wt% loaded AuNPs on g-C3N4 showed 99.01% of 4-nitrophenol, 97.70% of 3-nitrophenol and 98.50% of 2-nitrophenol photoreduction. The photocatalytic efficiency of Au/g-C3N4 was investigated under several parameters such as pH, initial nitrophenol concentration, and in presence of external inorganic anions. The mechanism of photoreduction of nitrophenol to aminophenol by Au/g-C3N4 was proposed based on the intermediate obtained from GCMS analysis. The observed higher catalytic activity of plasmonic hybrid photcatalysts is due to the synergic chemistry between the conduction band of g‐C3N4 and AuNP plasmonic band, which is well supported by PL, EIS, and transient photocurrent analysis. Kinetic rate constant for 3Au/g-C3N4 was found to be 0.43 min−1 at pH 3. Moreover, the rate of reaction significantly increased in presence of Cl−. ICP-OES analysis of as synthesised 3Au/g-C3N4 plasmonic photocatalyst shows there was no gold leaching even after ten cycles confirming the stability and reusability of the catalyst.

Second harmonic scattering multipole analysis of ligand-decorated gold nanoparticles

Ligand decoration of noble metallic nanoparticles is often needed for some applications, such as biochemical sensing, catalysis and nanotechnology, and the understanding of its process is of great importance. The second harmonic scattering (SHS) technique with advantages of surface-sensitivity and label-free detection, provides intrinsic information for such a research. In this work, the second harmonic(SH) scattering patterns of two types of ligands (cetyltrimethylammonium chloride and L-cysteine) capped gold nanoparticles (GNPs) with the same radii are measured. Both the intensities and shapes of the SH scattering patterns are changed after the ligand exchange process. In order to explain the pattern changes, the analytic expressions of SH scattering are derived theoretically for a relatively large nanoparticle based on Dadap’s multipolar theory. Considering the derived relationship between the multipole (up to octopole) contributions and the power of the nanosphere radius, the effective size effect is introduced to express the SH scattering signal change for different ligand decorations and well explain the experimental results. This theory provides a new perspective of the SH scattering response to different capping ligands and offers a possible quantitative method to analyze interface physical chemistry for ligands on the surface of nanoparticles.

Investigation of antibacterial properties of polyacrylonitrile fibers modified by new functional groups and silver nanoparticles.

This work reports the surface modification of polyacrylonitrile (PAN) fibers by graft copolymerization to ensure the decoration of homogenous and dense Ag nanoparticles. Two facile and subsequent modification processes resulted in a PAN fiber composite with an intact fibrous structure, sufficiently conductive for antistatic application and antibacterial activity. In the first step, some chemically attractive monomers and monomer mixtures, such as acrylic acid (AA), AA-itaconic acid (AA-IA), AA-acrylamide (AA-AAm), were introduced to the fiber surface by grafting. The grafting process was evidenced by FTIR, 1H-NMR, and SEM techniques. The second step aimed to form a chelate structure by Ag+ ions with the coordination centers imparted to the PAN structure, and then, Ag nanoparticles (AgNPs) were decorated on the copolymer fiber surfaces by reducing with the NaBH4. The presence, distribution, and changes that occurred after the AgNPs decoration were also monitored by the SEM technique. It was obtained that the AgNPs could not be easily removed from the composites, which presented an appearance as if they were dyed with Ag. It was determined that the composite fibers gained a certain degree of conductivity with the surface resistivity value of 109-102 Ω/cm2. The antibacterial activity of the composites against E. coli and S. aureus was examined by the zone of inhibition test compared to their detergent-washed samples.

Enhanced hydrogen sensing performances of PdO nanoparticles-decorated ZnO flower-like nanostructures

In this work, PdO nanoparticles-decorated ZnO flower-like nanostructures (PdO/ZnO) were synthesized by a one-step facile hydrothermal route and investigated their performance for hydrogen sensing applications. The structural and morphological characterizations were examined by XRD, FESEM, EDS, TEM, and XPS techniques and confirmed the homogenous decoration of PdO nanoparticles on the surface of ZnO flowers. UV-Vis spectroscopy and photoluminescence (PL) spectroscopy were used to investigate the optical characteristics. The ZnO and PdO/ZnO sensors were explored towards different target gases such as hydrogen (H2), carbon monoxide (CO), nitrogen dioxide (NO2), and ethanol. The concentration range of target gases was 2–100 ppm at an operating temperature range of 200–400 °C. It was concluded that PdO/ZnO flowers sensor showed high sensitivity, a speedy response time (20 s), and recovery time (960 s) towards H2 at 350 °C in comparison to the ZnO sensor. In addition, the PdO decorated ZnO flowers-based sensor showed high selectivity towards H2 against CO, NO2, and ethanol. This enhanced gas-sensing performance of the PdO/ZnO sensor has been attributed to the catalytic effect of PdO nanoparticles, and the formation of the PdO-ZnO p-n heterojunction, and their unique flower-like nanostructures. As a result, our research shows that coating PdO on ZnO flowers is an effective technique to improve hydrogen gas sensing performance and can be employed in various applications. The synergist impact of PdO nanoparticles, the arrangement of the PdO-ZnO p-n heterojunction, and their remarkable blossom-like nanostructures were the significant elements for improved gas-detecting execution of PdO/ZnO sensor.

Nanozyme-Triggered Cascade Reactions from Cup-Shaped Nanomotors Promote Active Cellular Targeting.

Self-propelled nanomotors have shown enormous potential in biomedical applications. Herein, we report on a nanozyme-powered cup-shaped nanomotor for active cellular targeting and synergistic photodynamic/thermal therapy under near-infrared (NIR) laser irradiation. The nanomotor is constructed by the asymmetric decoration of platinum nanoparticles (PtNPs) at the bottom of gold nanocups (GNCs). PtNPs with robust peroxidase- (POD-) like activity are employed not only as propelling elements for nanomotors but also as continuous O2 generators to promote photodynamic therapy via catalyzing endogenous H2O2 decomposition. Owing to the Janus structure, asymmetric propulsion force is generated to trigger the short-ranged directional diffusion, facilitating broader diffusion areas and more efficient cellular searching and uptake. This cascade strategy combines key capabilities, i.e., endogenous substrate-based self-propulsion, active cellular targeting, and enhanced dual-modal therapy, in one multifunctional nanomotor, which is crucial in advancing self-propelled nanomotors towards eventual therapeutic agents.

Decoration of Ru Nanoparticles on G-Alumina with Sub-Nanometer Ceria Species for Efficient Catalytic Ammonia Synthesis

Decoration of Ru Nanoparticles on G-Alumina with Sub-Nanometer Ceria Species for Efficient Catalytic Ammonia Synthesis

Luminescent properties of colloidal Ag-=SUB=-2-=/SUB=-S quantum dots for photocatalytic applications

The structural and optical properties of colloidal Ag2S quantum dots in various environments are investigated. With the help of transmission electron microscopy, X-ray diffraction and energy-dispersive X-ray analysis the formation of colloidal Ag2S quantum dots with an average size of 2-3 nm with a monoclinic crystal lattice, and Ag2S/SiO2 core-shell systems based on them, has been established. The change in the luminescence quantum yield of quantum dots with the change of the surface environment state is shown. The decoration of TiO2 nanoparticles of 10-15 nm in size with Ag2S quantum dots was performed and the influence of the structure of the interfaces of quantum dots and their environment (2-mercaptopropionic acid, water, ethylene glycol, SiO2 dielectric shell with a thickness of 0.6 nm and 2.0 nm) on the formation of TiO2-Ag2S heterosystems was analyzed. For Ag2S quantum dots passivated with 2-mercaptopropionic acid, signs of charge phototransfer after adsorption on TiO2 nanoparticles surface have been established. Signs of reactive oxygen species appearance due to charge phototransfer in heterosystem are enstablished, based on methylene blue photobleaching under excitation of heterosystem outside of TiO2 fundamental absorption region, Keywords: Quantum dots, photocatalysis, luminescence, titanium dioxide, silver sulfide.

Luminescent properties of colloidal Ag-=SUB=-2-=/SUB=-S quantum dots for photocatalytic applications

The structural and optical properties of colloidal Ag2S quantum dots in various environments are investigated. With the help of transmission electron microscopy, X-ray diffraction and energy-dispersive X-ray analysis the formation of colloidal Ag2S quantum dots with an average size of 2-3 nm with a monoclinic crystal lattice, and Ag2S/SiO2 core-shell systems based on them, has been established. The change in the luminescence quantum yield of quantum dots with the change of the surface environment state is shown. The decoration of TiO2 nanoparticles of 10-15 nm in size with Ag2S quantum dots was performed and the influence of the structure of the interfaces of quantum dots and their environment (2-mercaptopropionic acid, water, ethylene glycol, SiO2 dielectric shell with a thickness of 0.6 nm and 2.0 nm) on the formation of TiO2-Ag2S heterosystems was analyzed. For Ag2S quantum dots passivated with 2-mercaptopropionic acid, signs of charge phototransfer after adsorption on TiO2 nanoparticles surface have been established. Signs of reactive oxygen species appearance due to charge phototransfer in heterosystem are enstablished, based on methylene blue photobleaching under excitation of heterosystem outside of TiO2 fundamental absorption region, Keywords: Quantum dots, photocatalysis, luminescence, titanium dioxide, silver sulfide.

“Fabrication of Metal Oxide Nanoparticles Decorated Sepiolite-Polyvinyl Alcohol Nanocomposite Membranes for Water Cleanup

“Fabrication of Metal Oxide Nanoparticles Decorated Sepiolite-Polyvinyl Alcohol Nanocomposite Membranes for Water Cleanup

Dynamic Active Sites in Nife Oxyhydroxide Upon AU Nanoparticles Decoration for Highly Efficient Electrochemical Water Oxidation

Dynamic Active Sites in Nife Oxyhydroxide Upon AU Nanoparticles Decoration for Highly Efficient Electrochemical Water Oxidation

Bismuth Nanoparticles Decorated Vertically Arranged Graphene as Flexible Electrodes for Highly Efficient Detection of Pb(Ii) Ions in Water

Bismuth Nanoparticles Decorated Vertically Arranged Graphene as Flexible Electrodes for Highly Efficient Detection of Pb(Ii) Ions in Water

Opposite effects of gold and silver nanoparticle decoration of graphenic surfaces on bacterial attachment

The interaction between bacteria and nanoparticles is currently a central topic in bionanotechnology.

Green synthesis of microalgae-based carbon dots for decoration of TiO2 nanoparticles in enhancement of organic dye photodegradation

TiO2 is a well-known semiconductor used widely in the photocatalyst field, but its photocatalytic applications are hampered by a fast electron–hole recombination rate and low visible light absorption due to a wide-band-gap energy. Herein, we present a simple, low cost, and green approach to obtain carbon dots from microalgae, namely microalgae-based carbon dots (MCDs), using an unprecedented microwave-assisted treatment. The MCDs were successfully decorated on the surface of TiO2 nanoparticles. The as-prepared composite exhibited a superior photodegradation of methylene blue, compared with pristine TiO2 (83% and 27%, respectively) under visible light irradiation. The MCDs in TiO2-MCDs serve as electron reservoirs to trap photoinduced electrons and as photosensitizers for the improvement of visible light absorption; both factors play an important role in the improvement of the TiO2 photocatalytic activity. Furthermore, the as-prepared composite photocatalyst also exhibits high photostability and recyclability during the photodegradation of methylene blue. Therefore, this work provides an original approach to the development of environmentally friendly and highly effective photocatalysts for the treatment of various organic pollutants, which can go a long way toward ensuring a safe and sustainable environment.