In order to prepare self-standing and flexible slow neutron reflectors made of graphite fluoride (GF) with high contents of (CF) structural phase, graphite foils of different thicknesses were used as starting materials for gas (F)/solid fluorination. The maximal interlayer distance of GF was obtained with this phase thanks to the stacking sequence FCCF/FCCF; this is mandatory for the efficient reflection of slow neutrons. 71 and 77% of the (CF) phase were achieved for graphite foils with thicknesses of 1.
View Article and Find Full Text PDFResearchers are increasingly focusing on using biomass waste for green synthesis of nanostructured materials since green reducing, capping, stabilizing and orientation agents play a significant role in final application. Wheat peel extract contains a rich source of reducing and structure orienting agents that are not utilized for morphological transformation of NiO nanostructures. Our study focuses on the role of wheat peel extract in morphological transformation during the synthesis of NiO nanostructures as well as in non-enzymatic electrochemical urea sensing.
View Article and Find Full Text PDFThe ability to measure uric acid (UA) non-enzymatically in human blood has been demonstrated through the use of a simple and efficient electrochemical method. A phytochemical extract from radish white peel extract improved the electrocatalytic performance of nickel-cobalt bimetallic oxide (NiCoO) during a hydrothermal process through abundant surface holes of oxides, an alteration of morphology, an excellent crystal quality, and increased Co(III) and Ni(II) chemical states. The surface structure, morphology, crystalline quality, and chemical composition were determined using a variety of analytical techniques, including powder X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS).
View Article and Find Full Text PDFRecently, the nanostructured nickel-cobalt bimetallic oxide (NiCoO) material with high electrochemical activity has received intensive attention. Beside this, the biomass assisted synthesis of NiCoO is gaining popularity due to its advantageous features such as being low cost, simplicity, minimal use of toxic chemicals, and environment-friendly and ecofriendly nature. The electrochemical activity of spinel NiCoO is associated with its mixed metal oxidation states.
View Article and Find Full Text PDFThe electrochemical performance of NiCoO with urea precursors was evaluated in order to develop a non-enzymatic urea sensor. In this study, NiCoO nanostructures were synthesized hydrothermally at different concentrations of urea and characterized using scanning electron microscopy and X-ray diffraction. Nanostructures of NiCoO exhibit a nanorod-like morphology and a cubic phase crystal structure.
View Article and Find Full Text PDFIn this study, we have prepared cobalt selenide (CoSe) due to its useful aspects from a catalysis point of view such as abundant active sites from Se edges, and significant stability in alkaline conditions. CoSe, however, has yet to prove its functionality, so we doped palladium oxide (PdO) onto CoSe nanostructures using ultraviolet (UV) light, resulting in an efficient and stable water oxidation composite. The crystal arrays, morphology, and chemical composition of the surface were studied using a variety of characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy.
View Article and Find Full Text PDFThe surface tailored metal oxide nanostructures for the development of non-enzymatic sensors are highly demanded, but it is a big task due to the wide range of complexities during the growth process. The presented study focused on the surface modification of the heterogeneous morphology of cobalt oxide (CoO) prepared by the hydrothermal method. Further surface modification was conducted with the use of sodium citrate as a reducing and surface modifying agent for the CoO nanostructures through the high density of oxygenated terminal groups from the citrate ions.
View Article and Find Full Text PDFIn this study, chloride (Cl−) ions were successfully doped into ZnO nanostructures by the solvothermal method. The effect of various Cl− concentrations on the photocatalytic activity of ZnO towards the photodegradation of methylene blue (MB) under the illumination of ultraviolet light was studied. The as-prepared Cl−-doped ZnO nanostructures were analyzed in terms of morphology, structure, composition and optical properties.
View Article and Find Full Text PDFIn this study, we synthesized hybrid systems based on manganese oxide@zinc oxide (MnO@ZnO), using sol gel and hydrothermal methods. The hybrid materials exhibited hierarchical morphologies and structures characterized by the hexagonal phase of ZnO and the tetragonal phase of MnO. The hybrid materials were tested for degradation of methylene blue (MB), methyl orange (MO), and malachite green (MG) under ultraviolet (UV) light illumination.
View Article and Find Full Text PDFNanotechnology
November 2022
In this study, we have investigated the role of natural dead sea sponge (DSS, Porifera) as a three-dimensional (3D) porous host substrate for the immobilization of nanostructured ZnO material towards the development of ZnO based floating photocatalysts for efficient removal of methylene blue (MB) dye under the illumination of sunlight. After photodegradation, the treated water after dye degradation contains several pathogens, different disinfectants or chemical reagents that are essentially used. This is not the case for DSS as it can naturally kill any pathogens during the wastewater treatment process.
View Article and Find Full Text PDFThe present study is focused on yogurt as a simple, inexpensive, abundant, and green source for the preparation of luminescent carbon material for enhancing the photodegradation of methylene blue (MB). It introduces an ecological and sustainable approach for the large-scale production of carbon material using the direct thermal annealing of yogurt in a muffle furnace. The size of the as-prepared carbon material is about 200-300 nm, with average particle size distribution of 355 nm.
View Article and Find Full Text PDFThe present study demonstrates the crucial role of agave americana extract in enhancing the optical properties of zinc oxide (ZnO) through thermal treatment method. Various analytical and surface science techniques have been used to identify the morphology, crystalline structure, chemical composition, and optical properties, including scanning electron microscopy, x-ray diffraction, high resolution transmission electron microscopy (HRTEM), x-ray spectroscopy (EDS) and UV-visible spectroscopy techniques. The physical studies revealed the transformation of ZnO nanorods into nanosheets upon addition of an optimized amount of agave americana extract, which induced large amount of amorphous carbon deposited onto ZnO nanostructures as confirmed by HRTEM analysis.
View Article and Find Full Text PDFMetal-organic frameworks (MOFs) have been recently explored as crystalline solids for conversion into amorphous phases demonstrating non-specific mechanical, catalytic, and optical properties. The real-time control of such structural transformations and their outcomes still remain a challenge. Here, we use high-resolution transmission electron microscopy with 0.
View Article and Find Full Text PDFIn this study, we have used cotton silk as a source of abundant hydroxyl groups for the fast nucleation/growth of cobalt oxide (CoO) nanowires a hydrothermal method. The crystal planes of the CoO nanowires well matched the cubic phase. The as-synthesized CoO nanowires mainly contained cobalt and oxygen elements and were found to be highly sensitive towards uric acid in 0.
View Article and Find Full Text PDFActivation is commonly used to improve the surface and porosity of different kinds of carbon nanomaterials: activated carbon, carbon nanotubes, graphene, and carbon black. In this study, both physical and chemical activations are applied to graphene oxide by using CO and KOH-based approaches, respectively. The structural and the chemical properties of the prepared activated graphene are deeply characterized by means of scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectrometry and nitrogen adsorption.
View Article and Find Full Text PDFAdv Colloid Interface Sci
August 2021
Nanofluids which consist of nanoparticles added to conventional fluids (or base fluids) are considered as promising heat transfer fluids. Compared to metal, metal oxide nanoparticles and carbon nanotubes, graphene with its extremely high intrinsic thermal conductivity became the best candidate to design nanofluids. Such nanofluids have the potential to be highly-efficient heat transfer fluid by reducing loss of heat and increasing cooling rates.
View Article and Find Full Text PDFThe combination of exceptional functionalities offered by 3D graphene-based macrostructures (GBMs) has attracted tremendous interest. 2D graphene nanosheets have a high chemical stability, high surface area and customizable porosity, which was extensively researched for a variety of applications including CO adsorption, water treatment, batteries, sensors, catalysis, etc. Recently, 3D GBMs have been successfully achieved through few approaches, including direct and non-direct self-assembly methods.
View Article and Find Full Text PDFHigh-quality graphene is an especially promising carbon nanomaterial for developing nanofluids for enhancing heat transfer in fluid circulation systems. We report a complete study on few layer graphene (FLG) based nanofluids, including FLG synthesis, FLG-based nanofluid preparation, and their thermal conductivity. The FLG sample is synthesized by an original mechanical exfoliation method.
View Article and Find Full Text PDFSingle-walled carbon nanotubes (SWCNTs) were functionalized by ferrocene through ethyleneglycol chains of different lengths (FcETGn) and the functionalized SWCNTs (f-SWCNTs) were characterized by different complementary analytical techniques. In particular, high-resolution scanning electron transmission microscopy (HRSTEM) and electron energy loss spectroscopy (EELS) analyses support that the outer tubes of the carbon-nanotube bundles were covalently grafted with FcETGn groups. This result confirms that the electrocatalytic effect observed during the oxidation of the reduced form of nicotinamide adenine dinucleotide (NADH) co-factor by the f-SWCNTs is due to the presence of grafted ferrocene derivatives playing the role of a mediator.
View Article and Find Full Text PDFThe results of a study on the evolution of HiPco single-walled carbon nanotubes during the oxidizing action of H2 SO4 and HNO3 are presented. The process conditions used have been chosen so as to avoid any significant damage to the nanotube structure. The type and level of functionalization, the location of the grafted functions on the surface of the nanotube and the changes in morphological characteristics of the samples were examined by using a wide and complementary range of analytical techniques.
View Article and Find Full Text PDFThe effect of microwaves on the functionalization of single-walled carbon nanotubes (SWNTs) by the diazonium method was studied. The usage of a new approach led to the identification of the strength of the interaction (physical or chemical) between the functional groups and the carbon nanotube surface. Moreover, the nature (chemical formula) of the adsorbed/grafted functional groups was determined.
View Article and Find Full Text PDFSingle-wall carbon nanotubes (SWNTs) have been functionalized by a diazonium method through both a classical thermal reaction and a microwave-assisted reaction. The functionalized SWNTs have been characterized by nIR-Vis-UV absorption spectroscopy, Raman spectroscopy, and thermal gravimetric analysis. The results show that SWNTs are covalently functionalized through both reactions and that the microwave-assisted reaction is more rapid.
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