Nanocomposite Synthesis from a Natural Clay-Rich Soils and Exhausted Coffee Grounds for Environmental Applications

2020 ◽  
Vol 63 ◽  
pp. 47-63
Author(s):  
Vianey Urdapilleta-Inchaurregui ◽  
Fabián Fernández-Luqueño ◽  
Aidé Minerva Torres-Huerta ◽  
Daniela Roa-Velázquez ◽  
Francisco Javier Rodríguez-Varela ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Gas Adsorption ◽  
Energy Gap ◽  
Single Step ◽  
Natural Soil ◽  
Thermal Method ◽  
X Ray ◽  
Coffee Grounds

Natural clays, engineered Ag-nanoparticles (NP), TiO2-NP, and exhausted coffee grounds were used to synthesize a nanocomposite 7NC using a Vertisol soil through a single-step by thermal method, to build a nanomaterial to degrade or filtrate pollutants from soils, water or air. The surface characteristics and the porosity of the composite were studied through nitrogen gas adsorption at liquid nitrogen temperature and application of the Brunauer–Emmett–Teller (BET) equation and the results indicated that the microporous composites ranged a surface area of 17.36 m2 g-1. X-ray diffraction showed crystalline structure and crystalline phase of the nanocomposites. HR-TEM-STEM results demonstrated that TiO2-NP surrounded Ag-NP, and both were impregnated on natural soil nanoparticles. Oxidation states of the Ag-NP and TiO2-NP were analyzed by X-ray photoelectron spectroscopy (XPS) The energy gap of nanocomposite 7NC was determined using the Kubelka-Munck model from Ultraviolet–visible diffuse reflectance (UV–Visible DRS) spectra. The photocatalytic activity of these nanocomposites was evaluated, and the results indicated that nanocomposite with Vertisol-soil-NP (7NC) degraded the harmful organic compound methylene blue (MB) while the antimicrobial activity and resistance against Escherichia coli and Staphylococcus aureus and the zone of inhibition (ZOI) also were analyzed. The nanocomposites Ag-NP/TiO2-NP/natural-soil-NP/exhausted coffee-ground showed its for the development of an efficient material for environmental remediation with photocatalytic and antimicrobial activity.

Functionalized Polymeric Nanoparticles

2004 ◽  
Vol 818 ◽  
Author(s):  
Eric Sussman ◽  
Michael Clark ◽  
V. Prasad Shastri
Keyword(s):  
Drug Delivery ◽  
Photoelectron Spectroscopy ◽  
Cellular Localization ◽  
Polymeric Nanoparticles ◽  
Fluorescent Microscopy ◽  
Single Step ◽  
Layer By Layer ◽  
Bearing Surface ◽  
X Ray ◽  
Surface Functionality

AbstractSurface-functionalized polymeric nanoparticles (NP) are a versatile medium for drug delivery and imaging. The surface functionality is typically exploited to introduce molecules such as polymers and biomolecules to improve cellular localization, DNA binding and circulation. NP bearing surface functionality are typically prepared from polymers possessing functionalizable backbones or by layer-by-layer assembly of polyelectrolytes onto unmodified particles. We have developed a process to produce functionalized polymeric NP in a single step using non-functionalized polymers. This is achieved by the entrapment of polymeric functional moieties from an aqueous phase in a rapidly solidifying polymer core. NP were characterized using light scattering, scanning electron microscopy, zeta potential (ζ) measurement, fluorescent microscopy, and X-ray photoelectron spectroscopy (XPS). Stable NP ranging in diameter from 70 to 400nm with narrow polydispersity (PDI) can be produced by this process. The presence of functional moieties on the NP surface was verified by isoelectric point measurement and XPS. We foresee a number of uses for these functionalized nanoparticles, including drug delivery and modification of hard and soft material surfaces (both synthetic and biological) for tissue engineering.

Effects of DMSO Content on the Optical Properties, Liquid Stability, and Antimicrobial Activity of Fe3O4/OA/DMSO Ferrofluids

NANO ◽  
2020 ◽  
Vol 15 (05) ◽  
pp. 2050067 ◽  
Author(s):  
Rosy Eko Saputro ◽  
Ahmad Taufiq ◽  
Sunaryono ◽  
Nurul Hidayat ◽  
Arif Hidayat
Keyword(s):  
Antimicrobial Activity ◽  
Optical Properties ◽  
Energy Gap ◽  
Diffusion Method ◽  
Sonochemical Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Stability ◽  
Constituent Elements ◽  
Excellent Stability

Fe3O4 nanoparticles were synthesized through a sonochemical method and were subsequently investigated by X-ray diffraction (XRD), which showed that the phase obtained was Fe3O4 with the most intense peak at 2[Formula: see text] of 35.5∘. The particle size of the Fe3O4 nanoparticles was 11.4[Formula: see text]nm. The dried ferrofluids containing Fe3O4 as a filler, oleic acid (OA) and dimethyl sulfoxide (DMSO) as surfactants tended to be amorphous. Scanning electron microscopy (SEM) observation of the Fe3O4 nanoparticles revealed agglomeration, and the dried ferrofluids morphology showed excellent dispersion. The constituent elements of both the Fe3O4 nanoparticles and the Fe3O4/OA/DMSO ferrofluids were identified through energy-dispersive X-ray spectroscopy to be Fe, O and C. Fourier transform infrared (FTIR) investigation revealed functional groups of the Fe3O4/OA/DMSO ferrofluids constituent Fe3O4 as the filler, OA and DMSO as surfactants, and olive oil as a dispersant. The absorbance of the samples was characterized by UV–Vis spectrophotometry, and the results were used to calculate the energy gap of the Fe3O4/OA/DMSO ferrofluids ranged from 2.20[Formula: see text]eV to 2.45[Formula: see text]eV. Through the absorbance measurements, the optical properties of Fe3O4/OA/DMSO ferrofluids were evaluated on the basis of their refractive indices, which ranged from 2.86 to 3.02. The stability of the Fe3O4/OA/DMSO ferrofluids was characterized by transmittance data collected for 12[Formula: see text]h, and excellent stability was obtained, as indicated by a relatively stable transmittance. Last, the antimicrobial activity of the Fe3O4/OA/DMSO ferrofluids was assessed through the diffusion method; the results showed that increasing DMSO volume resulted in greater ferrofluid antimicrobial activity.

scholarly journals Photocatalytic Degradation of Diazinon with a 2D/3D Nanocomposite of Black Phosphorous/Metal Organic Framework

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 679
Author(s):  
Philani V. Hlophe ◽  
Langelihle N. Dlamini
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Electrochemical Impedance ◽  
Solar Spectrum ◽  
Black Phosphorus ◽  
X Ray ◽  
Visible Light Driven ◽  
Metal Organic

Metal–organic frameworks (MOFs) are promising materials for the removal and photodegradation of pesticides in water. Characteristics such as large surface area, crystalline structure and catalytic properties give MOFs an advantage over other traditional adsorbents. The application of MOFs in environmental remediation is hindered by their ability to only absorb in the UV region. Therefore, combining them with an excellent charge carrier 2D material such as black phosphorus (BP) provides an attractive composite for visible-light-driven degradation of pesticides. In the study, a nanocomposite of black phosphorus and MIL-125(Ti), defined as BpMIL, was prepared using a two-stage hydrothermal and sonication route. The as-prepared composite was characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) spectroscopy. These techniques revealed that the circular and sheet-like morphology of the nanocomposites had minimum charge recombination, allowing them to be effective photocatalysts. Furthermore, the photocatalysts exhibited extended productive utilization of the solar spectrum with inhibited recombination rate and could be applied in visible-light-driven water treatment. The photodegradation of diazinon in water was studied using a series of BpMIL (4%, 6% and 12% by mass) nanocomposites as a photocatalyst. The optimal composite was determined to be 4%BpMIL. The degradation parameters were optimized and these included photocatalyst dosage, initial diazinon concentration and pH of the solution. The optimal conditions for the removal and degradation of diazinon were: neutral pH, [diazinon] = 20 mg/L, photocatalyst dosage = 0.5 g/L, achieving 96% removal of the pesticide after 30 min with 4%BpMIL, while MIL-125(Ti) showed 40% removal. The improved photodegradation efficiency of the 4%BpMIL composite was attributed to Ti3+-Ti4+ intervalence electron transfer and the synergistic effect between MIL-125(Ti) and BP. The photodegradation followed pseudo-first-order kinetics with a rate constant of 1.6 × 10−2 min−1.

scholarly journals Photocatalytic and Antibacterial Potency of Titanium Dioxide Nanoparticles: A Cost-Effective and Environmentally Friendly Media for Treatment of Air and Wastewater

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 709
Author(s):  
Zohaib Razzaq ◽  
Awais Khalid ◽  
Pervaiz Ahmad ◽  
Muhammad Farooq ◽  
Mayeen Uddin Khandaker ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Titanium Dioxide Nanoparticles ◽  
Environmentally Friendly ◽  
Cost Effective ◽  
Bromophenol Blue ◽  
Bacterial Strains ◽  
Tio2 Nps ◽  
X Ray

Titanium dioxide nanoparticles (TiO2-NPs) were synthesized via a facile hydrothermal method. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared (FTIR), and Raman spectroscopy were used to study the structure, morphology, chemical composition, and functional group attached to the as-synthesized TiO2-NPs. These NPs were then used to test their efficacy against various microbes and their potency as effective catalysts. TiO2-NPs are found to have the maximum antibacterial activity against Gram-negative bacterial strains rather than Gram-positive bacteria. The photocatalytic activity of the TiO2-NPs was investigated for the photodegradation of 10 ppm bromophenol blue (BPB) dye by using 0.01 g–0.05 g of catalyst. TiO2-NPs exhibited the removal of 95% BPB, respectively, within 180 min. The TiO2-NPs’ antibacterial and catalytic properties suggest that these may be used in environmental remediation as a cost-effective and environmentally friendly wastewater and air treatment material.

scholarly journals Effect of the Incorporation of Titanium on the Optical Properties of ZnO Thin Films: From Doping to Mixed Oxide Formation

Coatings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 180 ◽  
Author(s):  
Miriam Yuste ◽  
Ramon Escobar-Galindo ◽  
Noelia Benito ◽  
Carlos Palacio ◽  
Oscar Martínez ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mixed Oxides ◽  
Energy Gap ◽  
Amorphous Structure ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Wide Range ◽  
Ti Content

ZnO films with Ti atoms incorporated (TZO) in a wide range (0–18 at.%) have been grown by reactive co-sputtering on silicon and glass substrates. The influence of the titanium incorporation in the ZnO matrix on the structural and optical characteristics of the samples has been determined by Rutherford backscattering spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results indicate that the samples with low Ti content (<4 at.%) exhibit a wurtzite-like structure, with the Ti4+ ions substitutionally incorporated into the ZnO structure, forming Ti-doped ZnO films. In particular, a very low concentration of Ti (<0.9 at.%) leads to a significant increase of the crystallinity of the TZO samples. Higher Ti contents give rise to a progressive amorphization of the wurtzite-like structure, so samples with high Ti content (≥18 at.%) display an amorphous structure, indicating in the XPS analysis, a predominance of Ti–O–Zn mixed oxides. The energy gap obtained from absorption spectrophotometry increases from 3.2 eV for pure ZnO films to 3.6 eV for those with the highest Ti content. Ti incorporation in the ZnO samples <0.9 at.% raises both the blue (380 nm) and green (approx. 550 nm) bands of the photoluminescence (PL) emission, thereby indicating a significant improvement of the PL efficiency of the samples.

scholarly journals Novel Route to Obtain Carbon Self-Doped TiO2 Mesoporous Nanoparticles as Efficient Photocatalysts for Environmental Remediation Processes under Visible Light

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3349 ◽  
Author(s):  
Pablo A. Ochoa Rodríguez ◽  
Tamara B. Benzaquén ◽  
Gina A. Pecchi ◽  
Sandra G. Casuscelli ◽  
Verónica R. Elías ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Synthesis Method ◽  
Mesoporous Structure ◽  
Acid Orange 7 ◽  
X Ray Diffraction ◽  
Visible Radiation ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption

Titanium dioxide materials were synthesized using two different methods. The samples were characterized by X-ray diffraction (XRD), UV–Visible diffusion reflectance spectroscopy (UV-Vis DR), Raman spectroscopy, N2 adsorption/desorption, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Although both kind of materials were found to have mesoporous structure and anatase crystalline phase, one of them was obtained from a synthesis method that does not involve the use of surfactants, and therefore, does not require calcination at high temperatures. This implies that the synthesized solid was self-doped with carbon species, coming only from the same source used for titanium. Then, the relationship between the presence of these species, the final calcination temperature, and the photocatalytic activity of the solids was studied in terms of the degradation and mineralization of an Acid Orange 7 aqueous solution, under visible radiation. A photosensitizing effect caused by the non-metal presence, that allows the solid to extend its absorption range, was found. Hence, a novel route to prepare C-modified photoactive mesoporous TiO2, simpler and cheaper, where neither a template nor an external carbon source is used, could be performed.

scholarly journals Fe + NNoncompensated Codoping TiO2Nanowires: The Enhanced Visible Light Photocatalytic Properties

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhongpo Zhou ◽  
Haiying Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Nitrogen Doping ◽  
Absorption Enhancement ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
Activity Increase ◽  
X Ray ◽  
Visible Light Range

TheFe + Ncodoped nanowire samples are prepared by hydro-thermal method and annealed in NH3atmosphere. The XRD (X-ray diffraction), SEM (Scanning electron microscope), UV-vis absorption spectroscopy, and BET (Brunauer, Emmett, and Teller) results indicate that the samples are pure anatase nanowires. TheFe + Ncodoped samples have the highest specific surface area, the largest red-shift, and the largest absorption enhancement in the visible light range compared with Fe doped, N doped, and undoped nanowires. The measurements of XPS (X-ray photoelectron spectroscopy) show that N content ofFe + Ncodoped TiO2is about two times as large as that of the N doped TiO2. It is assumed that nitrogen doping plays a very important role for the photocatalytic activity increase and hence theFe + Ncodoped nanowire TiO2shows the most effective photocatalytic activity under the visible light irradiation.

Highly Active Heterogeneous Fenton-Like Systems Based on Fe3O4 Nanoparticles

2011 ◽  
Vol 233-235 ◽  
pp. 487-490 ◽  
Author(s):  
Wei Wang ◽  
Tie Long Li ◽  
Ying Liu ◽  
Ming Hua Zhou
Keyword(s):  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Catalytic Efficiency ◽  
Alkaline Media ◽  
Homogeneous Catalyst ◽  
Fenton Reagent ◽  
Heterogeneous Fenton ◽  
X Ray

In this work, magnetic nanoscale Fe3O4 particles were synthesized through coprecipitation of Fe(II) and Fe(III) in alkaline media. The structure, composition and properties of the nanoparticles prepared were characterized by transmission electron microscope (TEM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM). Catalytic efficiency of the Fe3O4 nanoparticles was tested in degradation of phenol solution. At pH 7, the chemical oxygen demand (COD) removal rate reached 70% in 3 hours. The heterogeneous catalyst exhibited efficient catalytic activity close to that of iron homogeneous catalyst but with less than 3% leaching of irons cation. Further, it performed well under much wider pH range (pH 3~7) compared to classic Fenton reagent, providing potential alternative as a novel heterogeneous Fenton catalyst for environmental remediation.

scholarly journals One-Pot Decoration of Cupric Oxide on Activated Carbon Fibers Mediated by Polydopamine for Bacterial Growth Inhibition

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1158
Author(s):  
Hangil Moon ◽  
Young-Chul Lee ◽  
Jaehyun Hur
Keyword(s):  
Antimicrobial Activity ◽  
Activated Carbon ◽  
Surface Area ◽  
Bacterial Growth ◽  
Photoelectron Spectroscopy ◽  
Cupric Oxide ◽  
Activated Carbon Fiber ◽  
One Pot ◽  
Widespread Application ◽  
X Ray

Despite the widespread application of activated carbon fiber (ACF) filters in air cleaning owing to their high surface area and low price, they have certain limitations in that they facilitate bacterial growth upon prolonged use as ACF filters can provide favorable conditions for bacterial survival. The deposition of cupric oxide (CuO) on ACFs can be an effective way of resolving this problem because CuO can inhibit the proliferation of bacteria owing to its antimicrobial properties. However, finding a new method that allows the simple and uniform coating of CuO on ACF filters is challenging. Here, we demonstrate one-pot CuO deposition mediated by polydopamine (PD) to realize an ACF filter with antimicrobial activity. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) analyses reveal that CuO and PD are uniformly deposited on the ACF surface. The amount of CuO formed on the ACFs is measured by thermogravimetric analysis (TGA). Finally, the changes in surface area, pressure drop, and antimicrobial activity after coating PD-CuO on the ACFs are evaluated. The use of PD-CuO on the ACFs effectively suppresses the growth of bacteria and enhances the mechanical properties without significantly sacrificing the original characteristics of the ACF filter.

scholarly journals Photocatalytic and Oxidative Synthetic Pathways for Highly Efficient PANI-TiO2 Nanocomposites as Organic and Inorganic Pollutant Sorbents

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 441 ◽  
Author(s):  
Carolina Cionti ◽  
Cristina Della Pina ◽  
Daniela Meroni ◽  
Ermelinda Falletta ◽  
Silvia Ardizzone
Keyword(s):  
Reaction Mechanism ◽  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Pollutant Removal ◽  
Full Potential ◽  
X Ray ◽  
Molar Ratios ◽  
Inorganic Pollutant ◽  
Dye Sorption ◽  
Maximum Sorption

Polyaniline (PANI)-materials have recently been proposed for environmental remediation applications thanks to PANI stability and sorption properties. As an alternative to conventional PANI oxidative syntheses, which involve toxic carcinogenic compounds, an eco-friendly procedure was here adopted starting from benign reactants (aniline-dimer and H2O2) and initiated by ultraviolet (UV)-irradiated TiO2. To unlock the full potential of this procedure, we investigated the roles of TiO2 and H2O2 in the nanocomposites synthesis, with the aim of tailoring the properties of the final material to the desired application. The nanocomposites prepared by varying the TiO2:H2O2:aniline-dimer molar ratios were characterized for their thermal, optical, morphological, structural and surface properties. The reaction mechanism was investigated via mass analyses and X-ray photoelectron spectroscopy. The nanocomposites were tested on both methyl orange and hexavalent chromium removal. A fast dye-sorption was achieved also in the presence of interferents and the recovery of the dye was obtained upon eco-friendly conditions. An efficient Cr(VI) abatement was obtained also after consecutive tests and without any regeneration treatment. The fine understanding of the reaction mechanism allowed us to interpret the pollutant-removal performances of the different materials, leading to tailored nanocomposites in terms of maximum sorption and reduction capability upon consecutive tests even in simulated drinking water.

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