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Item type:Publication, Highly porous seeding-free boron-doped ultrananocrystalline diamond used as high-performance anode for electrochemical removal of carbaryl from water(Elsevier BV, 2022-06-25)Boron-doped diamond (BDD) electrodes are regarded as the most promising catalytic materials that are highly efficient and suitable for application in advanced electrochemical oxidation processes targeted at the removal of recalcitrant contaminants in different water matrices. Improving the synthesis of these electrodes through the enhancement of their morphology, structure and stability has become the goal of the material scientists. The present work reports the use of an ultranano-diamond electrode with a highly porous structure (B-UNCD WS /TDNT/Ti) for the treatment of water containing carbaryl . The application of the proposed electrode at current density of 75 mA cm −2 led to the complete removal of the pollutant (carbaryl) from the synthetic medium in 30 min of electrolysis with an electric energy per order of 4.01 kWh m −3 order −1 . The results obtained from the time-course analysis of the carboxylic acids and nitrogen-based ions present in the solution showed that the concentrations of nitrogen-based ions were within the established maximum levels for human consumption. Under optimal operating conditions, the proposed electrode was successfully employed for the complete removal of carbaryl in real water. Thus, the findings of this study show that the unique, easy-to-prepare BDD-based electrode proposed in this study is a highly efficient tool which has excellent application potential for the removal of recalcitrant pollutants in water. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effects of preparation method on catalytic behavior of Ni-Me (Me = Co, Nb)/?-Al2O3 for oxidative dehydrogenation of ethane(Sociedade Brasileira de Quimica, 2025-01-01)Catalysts based on Ni-Me (Me = Co, Nb) supported on γ-Al2O3 were prepared by the coprecipitation-chemical deposition method via reflux, and hydrothermal method for oxidative dehydrogenation of ethane. For coprecipitation method, ammonia and urea were used as precipitating agents. In both methods, the Ni content was 30 wt.%, whereas that of Me (Co, Ni) was 5 wt.%. The activity and selectivity towards ethylene appeared to depend strongly on the composition of the catalysts and, interestingly, on the preparation conditions. In the present article, it is shown that mixed hydrothermal samples using urea showed the best performance. Specifically, the hydrothermally prepared NiNb/γ-Al2O3 sample was the one that showed the highest values. The of Nb to Ni framework allowed to enrich with nucleophilic oxygen sites displayed via X-ray photoelectronic spectra (XPS) which lead to the formation of low reducible and selective sites.2 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Tailoring the Properties of Magnetite/PLA Nanocomposites: A Composition-Dependent Study(Multidisciplinary Digital Publishing Institute (MDPI), 2025)This study focused on composites of magnetite magnetic nanoparticles (MNP) and poly(lactic acid) (PLA) prepared via sonochemical synthesis. The evaluation of MNP loadings (2, 5, 10, 15, and 20 wt.%) provided insights into the structural and reactivity properties of the materials. Methods used included XRD, FT-IR and Raman spectroscopy, SEM and TEM microscopy, textural and thermal analysis (TG and DTA), and magnetic property measurements. The agreement between theoretical and experimental MNP loadings was good. XRD patterns showed predominantly MNP and semicrystalline phases, with a minor maghemite phase detected by FT-Raman and magnetic measurements. FT-IR analysis revealed interactions between MNP and PLA, confirmed by thermal analysis showing higher transition temperatures for the composites (145 °C) compared to pure PLA (139 °C). FT-Raman spectra also indicated that PLA helps prevent iron oxide oxidation, enhancing nanoparticle stability. SEM and TEM micrographs showed well-dispersed, spherical nanoparticles with minimal agglomeration, dependent on MNP loading. The nanocomposites exhibited low N₂ adsorption, resulting in low surface area (~2.1 m²/g) and porosity (~0.03 cm³/g). Magnetic analysis indicated that in the 2MNP/PLA sample, MNP were in a superparamagnetic-like regime at 300 K, suggesting good dispersion of 2 wt.% MNP in the PLA matrix.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Triboelectric Nanogenerators Based on Ulvan Biopolymer: Impact of Lithium Sulfate Doping on Electrical Output(John Wiley and Sons, 2025)The increasing demand for sustainable energy solutions has driven extensive research into energy harvesting devices, such as triboelectric nanogenerators (TENGs). Although various additives, including nanowires and salts, have been investigated to enhance the performance of biopolymer-based TENGs, the use of lithium salts in green algae-based TENGs remains unexplored. Herein, a series of TENGs are fabricated using ulvan, a biopolymer derived from the green algae Ulva nematoidea. To improve the output performance of these TENGs, the ulvan matrix is doped with lithium sulfate (Li2SO4) at concentrations of 0%, 10%, 20%, 30%, 40%, and 50% by weight. Dielectric permittivity measurements are conducted to calculate the surface charge density. The results show an increase from 0.94 nC cm−2 for the pristine film to 1.14 nC cm−2 at 30 wt% Li2SO4, beyond which further increases in salt concentration lead to a decrease in charge density. The incorporation of salts significantly enhances the electrical performance, with the 20% Li2SO4/ulvan device achieving a maximum power density of 0.156 W m−2, representing an 85.7% improvement compared to the pristine ulvan TENG. The open-circuit voltage (Voc) and short-circuit current also increase with salt concentration, with Voc reaching 87.71 V at 30% Li2SO4.1