Kinetics of the remediation of Arsenic-contaminated groundwater using nanoscale magnetite particles

2007 ◽  
Vol 1045 ◽  
Author(s):  
Parameswar Hari ◽  
Aaron Isley ◽  
Greg Medders ◽  
Gordon Purser
Keyword(s):  
Iron Oxide ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Mesh Size ◽  
Loop System ◽  
Nano Particles ◽  
Flow Loop ◽  
Inductively Coupled ◽  
Water Wells

AbstractArsenate species are toxic compounds widely found as contaminants in industrial and metallurgical environments. Environmental health problems related to industrial waste streams and related drinking water contaminations can commonly occur. Around the world, from Bangladeshi water wells to Oklahoman metal plating sites, toxic levels of arsenic (As) leach into potable water. This paper describes a flow loop system that relies on magnetic nanoscale particles, iron oxide (nanorust), for the removal of these toxic metals. The nanorust particles have an extremely high surface area which allows for the rapid removal of these metal oxides. Perhaps even more importantly, nanorust (iron oxide) also has the unique advantage that it can be easily removed and re-concentrated using inexpensive low field magnetic (125 T) separation techniques. In this study we will present results on treating low levels of As in water with nano particles of mesh size at 50 nm and 26 nm. Determination of As concentrations below 100 ppb level was attained using an Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) system and a continuous flow loop system.

scholarly journals Pd Nanoparticles Stabilized on the Cross-Linked Melamine-Based SBA-15 as a Catalyst for the Mizoroki–Heck Reaction

2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Surface ◽  
High Surface Area ◽  
Coupling Reaction ◽  
Pd Nanoparticles ◽  
Significant Activity ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Ft Ir

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract

Electron holography of catalysts

1995 ◽  
Vol 53 ◽  
pp. 416-417
Author(s):  
A. K. Datye ◽  
D. S. Kalakkad ◽  
L. F. Allard ◽  
E. Völkl
Keyword(s):  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Atomic Scale ◽  
Nano Particles ◽  
Phase Image ◽  
Electron Holography ◽  
Specimen Thickness ◽  
Phase Information ◽  
Particle Structure

The active phase in heterogeneous catalysts consists of nanometer-sized metal or oxide particles dispersed within the tortuous pore structure of a high surface area matrix. Such catalysts are extensively used for controlling emissions from automobile exhausts or in industrial processes such as the refining of crude oil to produce gasoline. The morphology of these nano-particles is of great interest to catalytic chemists since it affects the activity and selectivity for a class of reactions known as structure-sensitive reactions. In this paper, we describe some of the challenges in the study of heterogeneous catalysts, and provide examples of how electron holography can help in extracting details of particle structure and morphology on an atomic scale.Conventional high-resolution TEM imaging methods permit the image intensity to be recorded, but the phase information in the complex image wave is lost. However, it is the phase information which is sensitive at the atomic scale to changes in specimen thickness and composition, and thus analysis of the phase image can yield important information on morphological details at the nanometer level.

Ferrozine Assay for Simple and Cheap Iron Analysis of Silica-Coated Iron Oxide Nanoparticles

2018 ◽  
Author(s):  
Hattie Ring ◽  
Zhe Gao ◽  
Nathan D. Klein ◽  
Michael Garwood ◽  
John C. Bischof ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Hydrofluoric Acid ◽  
Inductively Coupled Plasma ◽  
Silica Shell ◽  
Oxide Nanoparticles ◽  
Inductively Coupled ◽  
Digestion Process ◽  
Plasma Methods ◽  
Iron Analysis

The Ferrozinen assay is applied as an accurate and rapid method to quantify the iron content of iron oxide nanoparticles (IONPs) and can be used in biological matrices. The addition of ascorbic aqcid accelerates the digestion process and can penetrate an IONP core within a mesoporous and solid silica shell. This new digestion protocol avoids the need for hydrofluoric acid to digest the surrounding silica shell and provides and accessible alternative to inductively coupled plasma methods. With the updated digestion protocol, the quantitative range of the Ferrozine assay is 1 - 14 ppm. <br>

Ferrozine Assay for Simple and Cheap Iron Analysis of Silica-Coated Iron Oxide Nanoparticles

2018 ◽  
Author(s):  
Hattie Ring ◽  
Zhe Gao ◽  
Nathan D. Klein ◽  
Michael Garwood ◽  
John C. Bischof ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Hydrofluoric Acid ◽  
Inductively Coupled Plasma ◽  
Silica Shell ◽  
Oxide Nanoparticles ◽  
Inductively Coupled ◽  
Digestion Process ◽  
Plasma Methods ◽  
Iron Analysis

The Ferrozinen assay is applied as an accurate and rapid method to quantify the iron content of iron oxide nanoparticles (IONPs) and can be used in biological matrices. The addition of ascorbic aqcid accelerates the digestion process and can penetrate an IONP core within a mesoporous and solid silica shell. This new digestion protocol avoids the need for hydrofluoric acid to digest the surrounding silica shell and provides and accessible alternative to inductively coupled plasma methods. With the updated digestion protocol, the quantitative range of the Ferrozine assay is 1 - 14 ppm. <br>

scholarly journals Solar-blind ultraviolet photodetector based on vertically aligned single-crystalline β-Ga2O3 nanowire arrays

Nanophotonics ◽  
2020 ◽  
Vol 9 (15) ◽  
pp. 4497-4503
Author(s):  
Liying Zhang ◽  
Xiangqian Xiu ◽  
Yuewen Li ◽  
Yuxia Zhu ◽  
Xuemei Hua ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Light Trapping ◽  
High Surface ◽  
Volume Ratio ◽  
Average Diameter ◽  
Nanowire Arrays ◽  
Etching Technique ◽  
Inductively Coupled ◽  
Solar Blind ◽  
Vertically Aligned

AbstractVertically aligned nanowire arrays, with high surface-to-volume ratio and efficient light-trapping absorption, have attracted much attention for photoelectric devices. In this paper, vertical β-Ga2O3 nanowire arrays with an average diameter/height of 110/450 nm have been fabricated by the inductively coupled plasma etching technique. Then a metal-semiconductor-metal structured solar-blind photodetector (PD) has been fabricated by depositing interdigital Ti/Au electrodes on the nanowire arrays. The fabricated β-Ga2O3 nanowire PD exhibits ∼10 times higher photocurrent and responsivity than the corresponding film PD. Moreover, it also possesses a high photocurrent to dark current ratio (Ilight/Idark) of ∼104 and a ultraviolet/visible rejection ratio (R260 nm/R400 nm) of 3.5 × 103 along with millisecond-level photoresponse times.

scholarly journals Characterization of Ag:Zno Thin Films and Their Use in Photoelectrocatalytic Degradation Of Methylene Blue (Mb)

2018 ◽  
Vol 22 (2) ◽  
pp. 109-116
Author(s):  
Bhishma Karki ◽  
Jeevan Jyoti Nakarmi ◽  
Rhiddi Bir Singh ◽  
Manish Banerjee
Keyword(s):  
Noble Metals ◽  
Spray Pyrolysis Technique ◽  
High Surface ◽  
High Surface Area ◽  
Nano Particles ◽  
Mixed Metal Oxide ◽  
Design And Synthesis ◽  
In Situ Deposition ◽  
Photoelectrocatalytic Degradation ◽  
Challenges And Opportunities

The synthesis of functional nano-particles via spray pyrolysis technique (SPT), especially those of catalytic nature, has attracted the interests of scientists and engineers, as well as industries. The rapid and high temperature continuous synthesis yields nano-particles with intrinsic features of active catalysts, that is, high surface area and surface energetic. For these reasons, SPT finds applications in various thermally inducible catalytic reactions. However, the design and synthesis of photocatalysts by SPT requires a knowledge set which is different from that established for thermal catalysts. Unknown to many, this has resulted in frustrations to those entering the field unprepared, especially since SPT appears to be an elegant tool in synthesizing oxide nano-particles of any elemental construct. From simple oxide to doped-oxide, and mixed metal oxide to the in situ deposition of noble metals, this Perspective gives an overview on the development of photocatalysts made by SPT in the last decade that led to a better understanding of the design criteria. Various challenges and opportunities are also highlighted; especially those beyond simple metal oxides, which perhaps contain the greatest potential for the exploitation of photocatalysts design by SPT. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, Page: 109-116

scholarly journals Solid State Electronic Sensors for Detection of Carbon Dioxide

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3848 ◽  
Author(s):  
Ami Hannon ◽  
Jing Li
Keyword(s):  
Carbon Dioxide ◽  
Iron Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Multiwall Carbon Nanotubes ◽  
High Sensitivity ◽  
Space Applications ◽  
Detection Range ◽  
Ultra Low Power ◽  
Compact Size

Detection of carbon dioxide (CO2) is very important for environmental, health, safety and space applications. We have studied novel multiwall carbon nanotubes (MWCNTs) and an iron oxide (Fe2O3) nanocomposite based chemiresistive sensor for detection of CO2 at room temperature. The sensor has been miniaturized to a chip size (1 cm × 2 cm). Good sensing performance was observed with a wide detection range of CO2 concentrations (100–6000 ppm). Structural properties of the sensing materials were characterized using Field-Emission Scanning Electron Microscopy, Fourier-Transform Infrared and Raman spectroscopies. The greatly improved sensitivity of the composite materials to CO2 can be attributed to the formation of a depletion layer at the p-n junction in an MWCNT/iron oxide heterostructure, and new CO2 gas molecules adhere to the high surface area of MWCNTs due to the concentration gradient. The test results showed that the CO2 sensor possesses fast response, compact size, ultra-low power consumption, high sensitivity and wide dynamic detection range.

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