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PdRuO2/PVP nanomaterial was synthesized using a straightforward method and characterized using advanced analytical methods such as TEM, XRD, XPS, elemental mapping and SEM. The synthesized PdRuO2/PVP nanomaterial was used as an ionophore in potentiometric sensor electrodes and successfully adapted to Cr3+ ion detection in a large number of aqueous samples. Several experimental parameters of the PdRuO2/PVP sensor such as potentiometric behavior, selectivity, repeatability, response time, pH, titration, and recovery in real samples were investigated. Potentiometric behavioral characteristics were performed in the concentration range 1 × 10−6–1.0 × 10−1 M. The repeated experiments performed six times showed that there was no deviation in the measurements. The limit of detection of the PdRuO2/PVP potentiometric sensor was very low with a value of 8.6 × 10−8 M. The potentiometric measurements showed that the synthesized PdRuO2/PVP ionophore was highly effective in detecting Cr3+ in a wide pH range of 2.0–8.0 and was found to have a shelf life of over 1 year. As a result, the synthesized PdRuO2/PVP electrode material was found to be highly selective, stable, and applicable for Cr3+ detection. [ABSTRACT FROM AUTHOR]

In the present work, SnO2-Fe3O4@MWCNT nanocatalyst was fabricated according to a sonochemical-hydrothermal procedure. The surface morphology and structure analyses of the synthesized SnO2-Fe3O4@MWCNT were investigated by transmission electron microscope (TEM), X-ray diffraction (XRD), Raman spectroscopy, EDS, FTIR and BET analyses. The degradation efficiency of SnO2-Fe3O4@MWCNT nanocatalyst in MB solution was tested by several experimental conditions such as SnO2-Fe3O4@MWCNT dosage (8–20 mg/L), initial MB concentration (20–50 mg/L), initial solution pH (5–9), and ultrasonic output power (37–60 kHz). SnO2-Fe3O4@MWCNT nanocatalyst retained its efficiency as 85% at common experimental conditions of 16 mg/L of SnO2-Fe3O4@MWCNTs, 45 mg/L of MB, pH of 8, H2O2 of 15 mM, and 60 kHz in 60 min under ultrasonic irradiation. In addition, the optimum experiment conditions for SnO2-Fe3O4@MWCNTs in MB degradation were investigated. The experiment result showed that the degradation efficiency of MB was increased by adding H2O2 to the reaction medium due to forming more free radicals. Further, it was detected that OH• radicals were determined to be the dominant oxidative species in MB degradation using SnO2-Fe3O4@MWCNT catalyst. The reuse tests showed that SnO2-Fe3O4@MWCNT sonocatalyst preserved its very stable structure after using the same catalyst 5 times. The intermediates and by-products after MB degradation using the catalyst were indicated by GC–MS analysis. Overall the results showed that the SnO2-Fe3O4@MWCNT sonocatalyst has excellent potential for treating organic pollutants in wastewater. [ABSTRACT FROM AUTHOR]

Supercapacitors have gained great interest due to their high-power energy density, suitability for clean energy and energy storage applications. In this study, we used commercial multi-walled carbon nanotube (MWCNT), polypyrrole (PPy) and synthesized porous carbon (PC) from Astragalus brachycalyx plant as supporting materials to prepare Pt-NiOx/PPy-MWCNT and Pt-NiOx/PC electrodes by a straightforward method and tested their electrochemical properties for supercapacitor applications. X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were employed to characterize synthesized electrodes. The XRD results confirmed the composition and crystalline structure of related materials in the Pt-NiOx/PPy-MWCNT and Pt-NiOx/PC electrodes. While the MWCNT supporting materials with PPy exhibited filled rod like structure, PC supporting materials showed porous surfaces according to SEM images. The EDS analysis approved chemical composition of the Pt-NiOx/PPy-MWCNT and Pt-NiOx/PC depending on their ingredients. Cyclic voltammetry (CV) measurements were used to characterize capacitor behaviors of the electrode materials in a Swagelok-type cell. The Pt-NiOx/PPy-MWCNT and Pt-NiOx/PC materials displayed 252.36 F/g and 390.97 F/g capacitance values, respectively. The electrochemical experiments revealed that the synthesized materials can be used as energy storage electrode materials for supercapacitor applications. [ABSTRACT FROM AUTHOR]

In this paper, we report the preparation of a new Fe3O4/SSIP/GO composite film for the purification of methylene blue dye from solution media. The preparation process of composite film was carried out to improve the interaction between the inner part of the sunflower stalk (SSIP) and surface matrix using magnetite/Graphene Oxide (Fe3O4/GO) minerals at weight ratios (0.2/4/0.2:w/w/w). The characterizations of as-developed Fe3O4/SSIP/GO composite film was successfully carried out by some advanced techniques such as FT-IR, SEM, and TGA analyses. Adsorption kinetic studies were evaluated in three different aspects as a pseudo-first-order model, pseudo-second-order model, and intraparticle diffusion-type model. Based on the R2 results, it was seen that the Pseudo-second order kinetic model (0.999) acted more harmoniously than the pseudo-first-order (0.960) and intra-particle diffusion technique models (0.974). In the light of these findings, it can be said that the prepared Fe3O4/SSIP/GO composite film used for removal of methylene blue dye can be considered as a promising material. [ABSTRACT FROM AUTHOR]

In this study, Fe3O4/Mn3O4/CuO nanoparticles were synthesized, characterized, and used as a nanocatalyst in methylene blue (MB) degradation under ultrasonic conditions. The synthesis of Fe3O4/Mn3O4/CuO nanoparticles was carried out according to a facile method and characterized using some analytical techniques such as FTIR, scanning electron microscopy (SEM) with transmission electron microscopy (TEM), EDS, and X-ray diffraction (XRD). The obtained Fe3O4/Mn3O4/CuO nanoparticles showed a very homogeneous structure, and the average particle size was determined as 1.87 nm. XRD analyses revealed that Fe3O4/Mn3O4/CuO nanoparticles have a 2.27 nm crystalline particle size. The chemical composition of Fe3O4/Mn3O4/CuO nanoparticles was well detected by FTIR and SEM–EDS analyses. The products formed after the degradation of MB were detected by gas chromatography–mass spectrometry (GC–MS). The degradation of MB was investigated with several experimental conditions using Fe3O4/Mn3O4/CuO nanoparticles, and optimum experiment conditions were detected to be [T] = 301 K, [MB] = 0.03 g/L, [Cat.] = 1.0 g/L, [H2O2] = 5 mM, [Ult.] = 60 kHz. A maximum of 95.04% MB degradation using Fe3O4/Mn3O4/CuO nanoparticles was achieved in 150 min. To detect the radical effectiveness, t-butanol, ethanol, and t-butanol scavenger solvents were tested, and it was detected that these scavenger solvents prevent the formation of radicals that are effective in MB degradation. As a result, the present work paves the way to prepare excellent and highly efficient sonocatalysts for the degradation of organic dyes. [ABSTRACT FROM AUTHOR]

The NiSnO2/biomass-derived porous carbon (PC) composites were synthesized from the roots of Astragalus brachycalyx fischer by using a series of physicochemical processes. Then, the composites were characterized by XRD, SEM, BET, Raman and EDS to illuminate and confirm the structures. The NiSnO2/biomass-derived PCs were employed as a new class of renewable supercapacitor electrodes. The electrochemical performance of the prepared PC electrodes was analyzed by using two electrodes in a 6 M potassium hydroxide (KOH) aqueous solution electrolyte. Electrochemical measurements revealed that NiSnO2/PC nanocomposites demonstrated highly effective stability with a specific capacitance of 295.90 F/g at 200 mV/s for supercapacitor studies, and a capacitance retention rate of 38.70% after 200 cycles. The high surface area and the presence of large hierarchical pores contributed to the effective electrochemical performance of the prepared nanocomposite materials. The NiSnO2/PC nanocomposites with the 3D porous structure have showed that promising efficiency in the application of supercapacitors with its high energy storage capacity and effective electrochemical performance. [ABSTRACT FROM AUTHOR]