Using New Porous Nanocomposites for Photocatalytic Water Decontamination

2008 ◽  
Vol 1145 ◽  
Author(s):  
Maryam Zarei Chaleshtori ◽  
S. M. Sarif Masud ◽  
Geoffrey B. Saupe
Keyword(s):  
Organic Contaminants ◽  
Heterogeneous Catalysts ◽  
Organic Pollutant ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Polluted Water ◽  
Particle Sizes ◽  
Water Decontamination ◽  
Physical And Chemical

AbstractHeterogeneous catalysts that accelerate the photolytic destruction of organic contaminants in water are a potentially inexpensive and highly effective way to remove both trace-level and saturated harmful compounds from industrial waste streams and drinking water. Porous photocatalytic materials can have the combined qualities of high surface area and relatively large particle sizes, as compared with nanoparticulate catalyst powders like titanium dioxide . The larger particle sizes of the porous materials facilitate catalyst removal from a solution, after purification has taken place.We have synthesized new kinds of photocatalytic porous oxide materials that can be used to purify contaminated water by accelerating the photodegradation of any kind of organic pollutant. The new materials have very large open pore structures that facilitate the diffusion, the surface contact of contaminants, and solvent flow through the catalyst. These qualities enhance surface reactions important to the process. The new catalysts have shown robust physical and chemical properties that make them candidates for real applications in polluted water decontamination.

scholarly journals SYNTHESIS, CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF CUO NANOPARTICLES

2019 ◽  
pp. 17-20 ◽  
Author(s):  
PARDEEP KUMAR ◽  
AJINKYA GIRISH NENE ◽  
SANDEEP PUNIA ◽  
MANOJ KUMAR ◽  
ZAHOOR ABBAS ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Bacterial Strains ◽  
Cuo Nps ◽  
Bacterial Infectious Disease ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Near Future

Objective: The present study was done to see the effect of biologically synthesized CuO-NPs (Copperoxide nanoparticles) on the growth of bacterial strains. Methods: Physico-chemical characterization of CuO-NPs was done by UV-Vis-spectrophotometer, XRD, FE-SEM, and EDS. The disc plate diffusion assay was used to evaluate the anti-bacterial effect of CuNPs. Results: This study has shown a promising anti-bacterial activity of biosynthesized CuO-NPs at different concentrations ranging from 10 to 100 µg/ml against Escherichia coli and Staphylococcus aureus bacteria. Conclusion: Nanoparticles (NPs) are small size particles between range 1 to 100 nm which expand their physical and chemical properties due to high surface area. The present study reveals that there may be possible utilization of biosynthesized CuO NPs for the treatment of bacterial infectious disease in near future.

Metal-free bifunctional graphene oxide-based carbocatalysts toward reforming biomass from glucose to 5-hydroxymethylfurfural

Nanoscale ◽  
2021 ◽  
Author(s):  
Minju Park ◽  
Joonhee Lee ◽  
Byeong-Su Kim
Keyword(s):  
Graphene Oxide ◽  
Surface Area ◽  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Metal Free ◽  
Boron Doped ◽  
Sulfonated Graphene

Graphene oxide (GO) and its derivatives are promising metal-free heterogeneous catalysts due to their high surface area and rich chemical properties. We developed a bifunctional boron-doped sulfonated graphene oxide (BS-GO)...

scholarly journals Characterization And Bioactivity Study of Chitosan Based Nanomaterial From Exoskeleton Waste of Parapaeneopsis Stylifera

2021 ◽  
Author(s):  
Vasantha Subramoniam Pramitha ◽  
Suhara Beevi Sajeetha ◽  
Hashim Alsif ◽  
Anil Aiswarya ◽  
Jameela Abdul Rasakh Fathima ◽  
...  
Keyword(s):  
Absorption Band ◽  
High Surface ◽  
Chitosan Nanoparticles ◽  
High Surface Area ◽  
Chemical Properties ◽  
Industrial Applications ◽  
Absorption Bands ◽  
Strong Activity ◽  
Stretching Vibration ◽  
Physical And Chemical

Abstract Chitosan based biomaterial have superior physical and chemical properties such as high surface area, porosity, tensile strength, conductivity as well as increased mechanical properties. Present study discusses about preparation of chitosan from shrimp (Parapenaeopsis stylifera) shell waste and its bioactivity effect. Demineralization, deproteinization and deacetylation was done to obtain chitosan and characterized by infrared spectroscopy and were plotted on all specimen over the frequency range of 4000-400cm− 1 at a resolution of 4cm− 1. Degree of deacetylation of chitosan was estimated with the produced spectra of sample. The DDA of extracted chitosan was found to be 89.91 % while the reference standard showed 81.27 %. The FTIR spectrum shows absoption band at 3450 cm− 1 (–OH stretching) because OH has highly intense absorption band and at about 2870 cm− 1 for the –C–H stretching because the intensity of peak is significant and the band does not involve in hydrogen bonding. It also has CH2 bending at 1420cm− 1 as well as the absorption band at about 1660cm− 1 for C = O in amide group. Apart from these bands, it shows absorption bands at 1030cm− 1and 1070cm− 1[C-O stretching]. It also contains NH group- stretching vibration at about 3360cm− 1. The absorption band at about 1730cm− 1 is for carbonyl group vibration. Many peaks of chitosan were observed, which shows a broad-OH stretching absorption band between 3450cm− 1. Another major absorption band is between 1220 and 1020 cm− 1 which represents the free amino group (-NH2) at C2 position of glucosamine, a major peak present in chitosan. Freshwater Chlorella, Chlorella marina and Pavlova lutheri showed maximum flocculation rate of 89%, 71% and 84% at pH 4.0 at a chitosan concentration level of 1% respectively. The results of synthesis of chitosan based nanoparticles by ionic gelation technique showed spherical morphology of the synthesized nanoparticles and the nature of functional groups present in chitosan nanoparticles were also confirmed by FT-IR and FE-SEM. Antibacterial study revealed that chitosan nanoparticles possess strong activity against Gram negative bacteria compared to Gram positive bacteria. Hence this investigation clearly suggests shellfish waste based chitosan could be used as an effective biomaterial in pharmaceutical as well as industrial applications.

scholarly journals Compositing Two-Dimensional Materials with TiO2 for Photocatalysis

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 590 ◽  
Author(s):  
Yu Ren ◽  
Yuze Dong ◽  
Yaqing Feng ◽  
Jialiang Xu
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Clean Energy ◽  
Two Dimensional ◽  
Preparation Methods ◽  
2D Material ◽  
Carrier Recombination ◽  
Two Dimensional Materials ◽  
Physical And Chemical

Energy shortage and environmental pollution problems boost in recent years. Photocatalytic technology is one of the most effective ways to produce clean energy—hydrogen and degrade pollutants under moderate conditions and thus attracts considerable attentions. TiO2 is considered one of the best photocatalysts because of its well-behaved photo-corrosion resistance and catalytic activity. However, the traditional TiO2 photocatalyst suffers from limitations of ineffective use of sunlight and rapid carrier recombination rate, which severely suppress its applications in photocatalysis. Surface modification and hybridization of TiO2 has been developed as an effective method to improve its photocatalysis activity. Due to superior physical and chemical properties such as high surface area, suitable bandgap, structural stability and high charge mobility, two-dimensional (2D) material is an ideal modifier composited with TiO2 to achieve enhanced photocatalysis process. In this review, we summarized the preparation methods of 2D material/TiO2 hybrid and drilled down into the role of 2D materials in photocatalysis activities.

A Systematic Study of the Catalytic Behavior at Enzyme–Metal-Oxide Nanointerfaces

Nano LIFE ◽  
2014 ◽  
Vol 04 (02) ◽  
pp. 1450005 ◽  
Author(s):  
Alan S. Campbell ◽  
Chenbo Dong ◽  
Andrew Maloney ◽  
Jeremy Hardinger ◽  
Xiao Hu ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Mechanical Stability ◽  
Metal Oxide Nanoparticles ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Catalytic Behavior ◽  
Physical And Chemical ◽  
And Chemical Properties

Metal-oxide nanoparticles with high surface area, controllable functionality and thermal and mechanical stability provide high affinity for enzymes when the next generation of biosensor applications are being considered. We report on the synthesis of metal-oxide-based nanoparticles (with different physical and chemical properties) using hydrothermal processing, photo-deposition and silane functionalization. Physical and chemical properties of the user-synthesized nanoparticles were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and Raman scattering, respectively. Thus, characterized metal-oxide-based nanoparticles served as nanosupports for the immobilization of soybean peroxidase enzyme (a model enzyme) through physical binding. The enzyme–nanosupport interface was evaluated to assess the optimum nanosupport characteristics that preserve enzyme functionality and its catalytic behavior. Our results showed that both the nanosupport geometry and its charge influence the functionality and catalytic behavior of the bio-metal-oxide hybrid system.

scholarly journals New insight into the photocatalytic degradation of organic pollutant over BiVO4/SiO2/GO nanocomposite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dang Trung Tri Trinh ◽  
Duangdao Channei ◽  
Auppatham Nakaruk ◽  
Wilawan Khanitchaidecha
Keyword(s):  
Photocatalytic Degradation ◽  
Surface Area ◽  
Removal Efficiency ◽  
Organic Pollutant ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Pollutant Removal ◽  
Phenol Removal ◽  
Adsorption Ability

AbstractThe nanocomposite of BiVO4-based material has been synthesized by one-step solvent method. The morphological, physical, chemical properties of the nanocomposite have been investigated. The results revealed that the surface area of BiVO4, BiVO4/SiO2 and BiVO4/SiO2/GO was 11.13, 28.47 and 43.93 m2/g, respectively. The structural test by XRD proved that the nanocomposites were monoclinic phase of bismuth vanadate. Adsorption and photocatalytic degradation were two main mechanisms that strongly related to pollutant removal efficiency (i.e., methylene blue and phenol). The BiVO4/SiO2/GO nanocomposite obtained the greatest MB removal efficiency due to its high adsorption ability from high surface area, whereas the photocatalytic degradation was insignificant mechanism. In contrast, the relatively low adsorption ability of BiVO4/SiO2/GO nanocomposite was observed when the pollutant was phenol due to negative charge and high stability of phenoxide ions, then the photocatalytic degradation became the main mechanism for phenol removal. The phenol removal efficiency reached approximately 70% in 6 h with H2O2 assistance. The combination of SiO2 and GO improved the surface property of BiVO4-based photocatalyst, however the excessive combination ratio generated the excellent adsorbent material rather than the photocatalyst. Hence, the optimal combination ratio is essential to archive the greatest nanocomposite for photocatalytic application.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

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.

Recent trends in carbon nanotubes based prostate cancer therapy: A biomedical hybrid for diagnosis and treatment

2021 ◽  
Vol 18 ◽  
Author(s):  
Raja Murugesan ◽  
Sureshkumar Raman
Keyword(s):  
Prostate Cancer ◽  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Drug Loading ◽  
High Surface ◽  
High Surface Area ◽  
High Capacity ◽  
Chemical Properties ◽  
Diagnosis And Treatment ◽  
High Level

: At present treatment methods for cancer are limited, partially due to the solubility, poor cellular distribution of drug molecules and, the incapability of drugs to annoy the cellular barriers. Carbon nanotubes (CNTs) generally have excellent physio-chemical properties, which include high-level penetration into the cell membrane, high surface area and high capacity of drug loading by in circulating modification with bio-molecules, project them as an appropriate candidate to diagnose and deliver drugs to prostate cancer (PCa). Additionally, the chemically modified CNTs which have excellent 'Biosensing' properties therefore makes it easy for detecting PCa without fluorescent agent and thus targets the particular site of PCa and also, Drug delivery can accomplish a high efficacy, enhanced permeability with less toxic effects. While CNTs have been mainly engaged in cancer treatment, a few studies are focussed on the diagnosis and treatment of PCa. Here, we detailly reviewed the current progress of the CNTs based diagnosis and targeted drug delivery system for managing and curing PCa.

scholarly journals Features of Waste Chemical Processing Germanium Concentrates

2020 ◽  
Author(s):  
Igor Nikolaevich Tanutrov ◽  
Marina Nikolaevna Sviridova
Keyword(s):  
Chemical Properties ◽  
Average Diameter ◽  
Toxic Waste ◽  
High Temperature Treatment ◽  
High Dispersion ◽  
Chemical Processing ◽  
Particle Sizes ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

In order to increase the extraction of germanium in the technology of production of germanium concentrates, as well as finding ways to eliminate the accumulation of toxic waste using modern techniques and equipment, the physical and chemical properties of waste chemical processing of germanium concentrates (OHGC) of two domestic enterprises were experimentally studied. The main components of OHGC are: sulphate hemihydrate CaSO4·0.5H2O and hypochlorite Ca(OCl)2 calcium. The moisture content of the sludge amounted to 30–50 %. The content of germanium in the cakes of both companies is in the range of 0.20 and 0.27 %, respectively, indicating the feasibility of recovery in the Ge. At the same time, the samples of cakes differ significantly in the content of impurities, which depends on the types of raw materials in the preparation of concentrates. Granulometric composition of cakes is characterized by high dispersion. With an average diameter of 12 μm, all particle sizes are in the range of 0.5-15 μm. The distribution of particle sizes is shifted in interval of 0–15 μm, and the area of the particles less than 3 μm is not more than 10 %. The high dispersion of the cake is reflected in the specific surface area, which is 23.7 m2/g. Thermographic study found that the heating of the sample cake is accompanied by two endothermic effects of dehydration at 110 and 145–168 ∘C calcium sulfate and hypochloride semihydrate with corresponding weight loss of 13.1 and 12.9 %. The presence of toxic impurities (arsenic, zinc and lead), as well as chlorine, presents significant challenges for the development of disposal technology with the extraction of germanium. Assuming that the undiscovered part of the germanium in the concentrate is compounds or solid solutions with silicon dioxide, an effective technology should include their reagent high temperature treatment. Keywords: waste, germanium concentrate, chemical processing, waste, physical and chemical properties

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