One-Pot Cu/TiO2 Nanoparticles Synthesis for Trans-Ferulic Acid Conversion into Vanillin

In this study, the co-synthesis of TiO2 and Cu metallic nanoparticles obtained via one-pot cost-efficient hydrothermal process has been addressed. Different nanocatalysts with Cu contents were characterized by X-ray diffraction, nitrogen porosimetry, scanning electron microscopy, and transmission electron microscopy. The TiO2 and Cu metallic nanoparticles were synthesized with copper loading up to one (Cu/Ti atomic ratio). Synthesized catalysts exhibited pore sizes in the mesoporous range and high surface areas above 150 m2/g. The particle size for TiO2 presented a homogeneous distribution of approximately 8 nm, moreover, Cu nanoparticles varied from 12 to >100 nm depending on the metal loading. The nanostructured materials were successfully tested in the conversion of trans-ferulic acid into vanillin under sustainable conditions, achieving the best performance for 0.3 Cu/Ti atomic ratio (70% vanillin yield).

Download Full-text

Synthesis and Optimization of Chitosan Nanoparticles Loaded with L-Ascorbic Acid and Thymoquinone

Nanomaterials ◽

10.3390/nano8110920 ◽

2018 ◽

Vol 8 (11) ◽

pp. 920 ◽

Cited By ~ 11

Author(s):

Nurhanisah Othman ◽

Mas Masarudin ◽

Cha Kuen ◽

Nurul Dasuan ◽

Luqman Abdullah ◽

...

Keyword(s):

Electron Microscopy ◽

Ascorbic Acid ◽

Infrared Spectroscopy ◽

Encapsulation Efficiency ◽

High Surface ◽

Chitosan Nanoparticles ◽

Polydispersity Index ◽

Ionic Gelation ◽

Surface Areas ◽

Efficient Delivery

The combination of compounds with different classes (hydrophobic and hydrophilic characters) in single chitosan carrier is a challenge due to the hydrophilicity of chitosan. Utilization of l-ascorbic acid (LAA) and thymoquinone (TQ) compounds as effective antioxidants is marred by poor bioavailability and uptake. Nanoparticles (NPs) solved the problem by functioning as a carrier for them because they have high surface areas for more efficient delivery and uptake by cells. This research, therefore, synthesized chitosan NPs (CNPs) containing LAA and TQ, CNP-LAA-TQ via ionic gelation routes as the preparation is non-toxic. They were characterized using electron microscopy, zetasizer, UV–VIS spectrophotometry, and infrared spectroscopy. The optimum CNP-LAA-TQ size produced was 141.5 ± 7.8 nm, with a polydispersity index (PDI) of 0.207 ± 0.013. The encapsulation efficiency of CNP-LAA-TQ was 22.8 ± 3.2% for LAA and 35.6 ± 3.6% for TQ. Combined hydrophilic LAA and hydrophobic TQ proved that a myriad of highly efficacious compounds with poor systemic uptake could be encapsulated together in NP systems to increase their pharmaceutical efficiency, indirectly contributing to the advancement of medical and pharmaceutical sectors.

Download Full-text

Metal Nanoparticles Supported on Al-MCM-41 via In Situ Aqueous Synthesis

Journal of Nanomaterials ◽

10.1155/2010/302898 ◽

2010 ◽

Vol 2010 ◽

pp. 1-8 ◽

Cited By ~ 5

Author(s):

Ivonne Alonso-Lemus ◽

Ysmael Verde-Gomez ◽

Alfredo Aguilar-Elguézabal ◽

Lorena Álvarez-Contreras

Keyword(s):

Metallic Nanoparticles ◽

High Surface ◽

Textural Properties ◽

Active Phase ◽

Ruthenium Catalysts ◽

Aqueous Synthesis ◽

Surface Areas ◽

Electrochemical Testing ◽

Size And Morphology ◽

Mcm 41

MCM-41 have been used to custom synthesize catalysts in because of the controllable properties, such as pore size, active phase incorporation, crystal size, and morphology, among others. In this paper, a simple and versatile method for the incorporation of platinum, ruthenium, and palladium onto Al-MCM-41 mesoporous silica by direct inclusion of various precursors was studied. M/Al-MCM-41 structure, textural properties, morphology, and elemental composition were analyzed. The results obtained indicate that the Al-MCM-41 mesoporous-ordered structure was not affected by metallic particle incorporation. High-surface areas were obtained (1131 m2/g). Metallic nanoparticles dispersion on Al-MCM-41 was homogeneous for all samples and its particles sizes were between 6 nm to 20 nm. Microscopy results show round shape particles in platinum and palladium samples; however, ruthenium catalysts exhibit a spherical and rod shapes. Electrochemical testing for Pt/Al-MCM-41 showed electrocatalytic activity forH2oxidation which indicates that these materials can be used as a catalyst in electrochemical devices.

Download Full-text

Characterization of Ternary CuNiCo Metallic Nanoparticles Produced by Hydrogen Reduction

Materials ◽

10.3390/ma14206006 ◽

2021 ◽

Vol 14 (20) ◽

pp. 6006

Author(s):

Eliana Paola Marín Castaño ◽

José Brant de Campos ◽

Ivan Guillermo Solórzano-Naranjo ◽

Eduardo de Albuquerque Brocchi

Keyword(s):

Electron Microscopy ◽

Metallic Nanoparticles ◽

Hydrogen Reduction ◽

Homogeneous Distribution ◽

Homogeneous Material ◽

Chemical Route ◽

Alloy Particles ◽

Lower Temperature ◽

Physical And Chemical

Different methods of producing nanostructured materials at the laboratory scale have been studied using a variety of physical and chemical techniques, though the challenge here is the homogeneous distribution of the elements which also depends on the precursor elements. This work thus focused on the micro-analytical characterization of Cu–Ni–Co metallic nanoparticles produced by an alternative chemical route aiming to produce solid solution nanoparticles. This method was based on two steps: the co-formation of oxides by nitrates’ decomposition followed by their hydrogen reduction. Based on the initial composition of precursor nitrates, three homogeneous ternaries of the Ni, Cu and Co final alloy products were pre-established. Thus, the compositions in %wt of the synthesized alloy particles studied in this work are 24Cu–64Ni–12Co, 12Cu–64Ni–24Co and 10Cu–80Ni–10Co. Both precursor oxides and metallic powders were characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM/EDS) and transmission electron microscopy (TEM). The results show that the synthesis procedure was successful since it produced a homogeneous material distributed in different particle sizes depending on the temperature applied in the reducing process. The final composition of the metallic product was consistent with what was theoretically expected. Resulting from reduction at the lower temperature of 300 ∘C, the main powder product consisted of particles with a spheroidal and eventually facetted morphology of 50 nm on average, which shared the same FCC crystal structure. Particles smaller than 100 nm in the Cu–Ni–Co alloy agglomerates were also observed. At a higher reduction temperature, the ternary powder developed robust particles of 1 micron in size, which are, in fact, the result of the coarsening of several nanoparticles.

Download Full-text

Development of Binder Free Interconnected 3D Flower of NiZn2O4 as an Advanced Electrode Materials for Supercapacitor Applications

Crystals ◽

10.3390/cryst12010014 ◽

2021 ◽

Vol 12 (1) ◽

pp. 14

Author(s):

Sajid Ali Ansari ◽

Nazish Parveen ◽

Mohd Al Saleh Al-Othoum ◽

Mohammad Omaish Ansari

Keyword(s):

Electron Microscopy ◽

Energy Storage ◽

Active Sites ◽

Electrode Materials ◽

Electrochemical Impedance ◽

Nickel Foam ◽

High Surface ◽

Hydrothermal Process ◽

Active Material ◽

Binder Free

The design and development of electrode materials for energy-storage applications is an area of prime focus around the globe because of the shortage of natural resources. In this study, we developed a method for preparing a novel three-dimensional binder-free pseudocapacitive NiZn2O4 active material, which was grown directly over nickel foam (NiZn2O4@3D-NF), using a simple one-step hydrothermal process. The material was characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy techniques were employed to evaluate the pseudocapacitive performance of the NiZn2O4 active material in a three-electrode assembly cell. The prepared NiZn2O4@3D-NF electrode exhibited an excellent specific capacitance, of 1706.25 F/g, compared to that of the NiO@3D-NF (1050 F/g) electrode because it has the bimetallic characteristics of both zinc and nickel. The NiZn2O4@3D-NF electrode showed better cyclic stability (87.5% retention) compared to the NiO@3D-NF electrode (80% retention) after 5000 cycles at a fixed current density, which also supports the durability of the NiZn2O4@3D-NF electrode. The characteristics of NiZn2O4@3D-NF include corrosion resistance, high conductivity, an abundance of active sites for electrochemical reaction, a high surface area, and synergism between the bimetallic oxides, which make it a suitable candidate for potential application in the field of energy storage.

Download Full-text

Small AgNP in the Biopolymer Nanocomposite System

International Journal of Molecular Sciences ◽

10.3390/ijms21249388 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9388

Author(s):

Małgorzata Zienkiewicz-Strzałka ◽

Anna Deryło-Marczewska

Keyword(s):

Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Metallic Nanoparticles ◽

Silver Ions ◽

Membrane System ◽

Added Value ◽

Ex Situ ◽

Membrane Properties ◽

Homogeneous Distribution

In this work, ultra-small and stable silver nanoparticles (AgNP) on chitosan biopolymer (BP/AgP) were prepared by in situ reduction of the diamminesilver(I) complex ([Ag(NH3)2]+) to create a biostatic membrane system. The small AgNP (3 nm) as a stable source of silver ions, their crystal form, and homogeneous distribution in the whole solid membrane were confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The X-ray photoelectron spectroscopy (XPS) and Auger analysis were applied to investigate the elemental composition, concentration, and chemical state of surface atoms. It was found that ultra-small metallic nanoparticles might form a steady source of silver ions and enhance the biostatic properties of solid membranes. Ultra-small AgNP with disturbed electronic structure and plasmonic properties may generate interaction between amine groups of the biopolymer for improving the homogeneity of the nanometallic layer. In this work, the significant differences between the typical way (deposition of ex-situ-prepared AgNP) and the proposed in-situ synthesis approach were determined. The improved thermal stability (by thermogravimetry and differential scanning calorimetry (TG/DSC) analysis) for BP/AgP was observed and explained by the presence of the protective layer of a low-molecular silver phase. Finally, the antibacterial activity of the BP/AgP nanocomposite was tested using selected bacteria biofilms. The grafted membrane showed clear inhibition properties by destruction and multiple damages of bacteria cells. The possible mechanisms of biocidal activity were discussed, and the investigation of the AgNP influence on the bacteria body was illustrated by AFM measurements. The results obtained concluded that the biopolymer membrane properties were significantly improved by the integration with ultra-small Ag nanoparticles, which added value to its applications as a biostatic membrane system for filtration and separation issues.

Download Full-text

In-Situ Construction of Bi2O3/Bi2SiO5 Heterojunction Photocatalyst On The Exfoliated Bentonite With Efficient Photocatalytic Performance

10.21203/rs.3.rs-306813/v1 ◽

2021 ◽

Author(s):

Tao Nie ◽

Ben Chen ◽

Yuyang Huang ◽

Rui Wang ◽

Beibei He ◽

...

Keyword(s):

Photocatalytic Performance ◽

One Pot ◽

Characterization Methods ◽

Contaminant Degradation ◽

Simulated Solar Light ◽

Surface Areas ◽

Photocatalytic Application ◽

Cost Efficient ◽

The Cost

Abstract In this study, Bi2O3/Bi2SiO5 heterojunction were in-situ constructed on the exfoliated bentonite via a novel one-pot method. The crystal structure, morphology, and optical features for the as-synthesized Bi2O3/Bi2SiO5 heterojunctions were systematically characterized by a series of characterization methods. During the preparation process, the exfoliated bentonite acted as the Si source and framework for the in-situ formation of Bi2O3/Bi2SiO5 p-n heterogeneous junction on the bentonite interlayer. As a result, the Bi2O3/Bi2SiO5 photocatalyst exhibited a superior photocatalytic performance than that of bare α-Bi2O3 toward the decomposition of Rhodamine B (RhB) via the simulated solar light irradiation, which was due to the synergetic effects of large specific surface areas and p-n junction between Bi2SiO5 and Bi2O3. Moreover, a probable photocatalytic mechanism for the as-prepared photocatalysts was explored. This work provides a new insight into building the cost-efficient photocatalysts for the contaminant degradation and a latent photocatalytic application of bentonite.

Download Full-text

Functionalization of Mesoporous SBA-15 with APTES by Co-Condensation and its Effect on Immobilization of Candida rugosa Lipase

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.645-646.1261 ◽

2015 ◽

Vol 645-646 ◽

pp. 1261-1266 ◽

Cited By ~ 1

Author(s):

Xiu Yan Li ◽

Yun Qiang Xu ◽

Guo Wei Zhou

Keyword(s):

Electron Microscopy ◽

Enzymatic Activity ◽

Hydrothermal Process ◽

Candida Rugosa ◽

Molar Ratio ◽

Surface Areas ◽

Transmission Electron ◽

Effects Of Ph ◽

Loading Amount ◽

Hydrolysis Of

Functionalized SBA-15 with mesoscopic pore channels was synthesized by co-condensation of tetraethoxysilane and (3-aminopropyl) triethoxysilane (APTES) via hydrothermal process. Small-angle X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy were used to monitor the effect of surface functionalization on the structural and textural features of the SBA-15. The results suggested that the structural ordering of functionalized SBA-15, as well as pore diameters, pore volumes and surface areas, were decreased with increasing the APTES molar ratio. Candida rugosa lipase (CRL) was used as a model enzyme for studying the effect of amino-functionalized on loading amount and enzymatic activity. The effects of pH and temperature on catalytic hydrolysis of tributyrin by immobilized CRL were investigated. The results showed that immobilized CRL had a well adaptability in a wide pH and temperature region, and CRL immobilized on functionalized SBA-15 exhibited much higher enzymatic activity than free CRL, especially, 5 mol% APTES functionalized SBA-15 immobilized CRL displayed the highest activity.

Download Full-text

Low Temperature Methanation of CO2 on High Ni Content Ni-Ce-ZrOδ Catalysts Prepared via One-Pot Hydrothermal Synthesis

Catalysts ◽

10.3390/catal10010032 ◽

2019 ◽

Vol 10 (1) ◽

pp. 32 ◽

Cited By ~ 2

Author(s):

Vissanu Meeyoo ◽

Noppadol Panchan ◽

Nat Phongprueksathat ◽

Atsadang Traitangwong ◽

Xinpeng Guo ◽

...

Keyword(s):

Hydrothermal Synthesis ◽

Low Temperature ◽

High Surface ◽

Oxygen Species ◽

Co2 Conversion ◽

One Pot ◽

Co2 Methanation ◽

Surface Areas ◽

Ni Content ◽

Methane Selectivity

Ni-Ce-Zr-Oδ catalysts were prepared via one-pot hydrothermal synthesis. It was found that Ni can be partially incorporated into the Ce-Zr lattice, increasing surface oxygen species. The catalysts possess high surface areas even at high Ni loadings. The catalyst with Ni content of 71.5 wt.% is able to activate CO2 methanation even at a low temperature (200 °C). Its CO2 conversion and methane selectivity were reported at 80% and 100%, respectively. The catalyst was stable for 48 h during the course of CO2 methanation at 300 °C. Catalysts with the addition of medium basic sites were found to have better catalytic activity for CO2 methanation.

Download Full-text

Preparation and characterization of porous TiO2-SiO2 mixed oxide

MRS Proceedings ◽

10.1557/proc-848-ff3.25 ◽

2004 ◽

Vol 848 ◽

Author(s):

Ang Thiam Peng ◽

Zhong Ziyi ◽

James Highfield

Keyword(s):

Electron Microscopy ◽

Mixed Oxide ◽

Mixed Oxides ◽

Structural Information ◽

High Surface ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Surface Areas ◽

Transmission Electron

ABSTRACTA study on the comparison of porous TiO2-SiO2 mixed oxides synthesized variously via the “amine directed” method is reported. The amine capping groups were octylamine, dodecylamine, octyldecylamine, aniline, and isobutylamine. The mixed oxide is characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), infrared spectroscopy (IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Brunauer-Emmett-Teller analysis (BET). While XRD, SEM and TEM provide mainly (bulk) structural information on the mixed oxide preparations, BET (N2 physisorption) probes into their surface area and texture. IR evidence suggests that intimate chemical mixing of both oxides has occurred, while BET measurements show that high surface areas are attainable and that the mixed oxide is more thermally stable than pure (control) samples of TiO2.

Download Full-text

Photocatalytic decoloration of Acid Red 27 in presence of SnO2 nanoparticles

Water Science & Technology ◽

10.2166/wst.2010.156 ◽

2010 ◽

Vol 62 (6) ◽

pp. 1256-1264 ◽

Cited By ~ 6

Author(s):

A. Esmaielzadeh Kandjani ◽

M. Farzalipour Tabriz ◽

N. A. Arefian ◽

M. R. Vaezi ◽

F. Halek ◽

...

Keyword(s):

Rate Constant ◽

Sno2 Nanoparticles ◽

High Surface ◽

Hydrothermal Process ◽

High Surface Area ◽

Reaction Rate Constant ◽

Kinetic Rate Constant ◽

Kinetic Rate ◽

Surface Areas ◽

Crystallite Sizes

In this paper, the photocatalytic decoloration of Acid Red 27 (AR27) has been investigated using ultraviolet (UV) irradiation in presence of SnO2 nanoparticles. SnO2 nanoparticles were synthesized via hydrothermal process. The SnO2 nanoparticles' average crystallite sizes derived from X-ray analyses which were synthesized for 2, 12 and 24 hrs were about 3.73, 5.31 and 7.6 nm, respectively. Brunauer-Emmett-Teller (BET) analyses showed high surface area of about 183, 120 and 90(m2/g), respectively for aforementioned synthesized samples. Our investigations indicated that reaction rate constant and photocatalytic efficiency of AR27 decoloration have a direct relation with SnO2 nanoparticles' specific surface areas and band gap energies. Decoloration kinetics was investigated by using Langmuir–Hinshelwood model. The values of the adsorption equilibrium constant, K[AR27], and the kinetic rate constant of surface reaction, kc, were found to be 0.0924 (l/mg) and 0.2535 (mg/l min), respectively.

Download Full-text