Nitrogen and sulfur co-doped activated carbon nanosheets for high-performance coin cell supercapacitor device with outstanding cycle stability

Herein, we report the utilization of nitrogen and sulfur dual heteroatoms co-doped activated carbon (NSAC) by hydrothermal method for electrochemical supercapacitors. Various NSACs were made by using a fixed amount of activated carbon and changing the amounts of thioacetamide. From NSAC electrodes, the coin cell configuration was fabricated and the overall electrochemical conduct was evaluated by using cyclic voltammetry, galvanostatic charge-discharge, cycle life, and electrochemical impedance methodologies. The outcomes manifest that co-doping sulfur and nitrogen into the AC improves the electrochemical performance. In comparison to pure activated carbon, the optimized NSAC produced a higher specific capacitance value of 417 F g−1 at 0.7 A g−1 and also demonstrated outstanding charge-discharge cycling stability at 7 mA (5 A g−1), maintaining 76% of its opening capacitance after 60,000 cycles in the CR2032 device configuration. The impedance studies phase angle value of 85° has added evidence of the NSAC’s good capacitor performance. Thus, we believe this work is suitable for practical applications for energy storage devices. Graphical abstract: [Figure not available: see fulltext.]This work was supported by Qatar University through a National Capacity Building Program Grant (NCBP) [QUCP-CAM-20/23-463]. The publication of the article was funded by the Qatar National Library. Statements made herein are solely the responsibility of the authors

UV Induced Photodegradation of Direct Green dye by Tb-doped La10Si6O27 Catalyst

Due to the expansion of industry, the world's population growth has led to increased air and water contamination. Because they are poisonous and non-biodegradable, organic dyes are a significant source of this contamination. Studies have concentrated on photocatalysts to transform organic dyes into innocuous compounds in order to lessen the harm that organic colours cause. In this study, solution combustion technique was employed to prepare rare-earth metal (terbium (Tb)) doped lanthanum silicate phosphor (La10Si6O27) using lanthanum nitrate and fumed silica were utilized as precursors, oxalyldihydrazide was used as fuel, and terbium nitrate was used as a dopant. The photocatalytic activities for the Direct Green-23 (DG23) dye degradation under UV irradiation were studied and found that 59.05% of dyes degraded at 120 min. These findings shows that, La10Si6O27 is a promising material for industrial dye degradation since 59.05% of the dyes were absorbed by the material in 120 min.This work was supported by Qatar University through a National Capacity Building Program Grant (NCBP), [QUCP-CAM-2022-463]. The publication of the article was funded by Qatar National Library

Progressive Review of Functional Nanomaterials-Based Polymer Nanocomposites for Efficient EMI Shielding

Nanomaterials have assumed an imperative part in the advancement of human evolution and are more intertwined in our thinking and application. Contrary to the conventional micron-filled composites, the unique nanofillers often modify the properties of the polymer matrix at the same time, bestowing new functionality because of their chemical composition and their nano dimensions. The unprecedented technological revolution is driving people to adapt to miniaturized electronic gadgets. The sources of electromagnetic fields are ubiquitous in a tech-driven society. The COVID-19 pandemic has escalated the proliferation of electromagnetic interference as the world embraced remote working and content delivery over mobile communication devices. While EMI shielding is performed using the combination of reflection, absorption, and electrical and magnetic properties, under certain considerations, the dominant nature of any one of the properties may be required. The miniaturization of electronic gadgets coupled with wireless technologies is driving us to search for alternate lightweight EMI shielding materials with improved functionalities relative to conventional metals. Polymer nanocomposites have emerged as functional materials with versatile properties for EMI shielding. This paper reviews nanomaterials-based polymer nanocomposites for EMI shielding applications.This work was supported by Qatar University through a National Capacity Building Program Grant (NCBP), [QUCP-CAM-20/23-463]. Statements made herein are solely the responsibility of the authors

Recent Advances in Copper-Based Materials for Sustainable Environmental Applications

In recent years, copper-based nanomaterials have gained significant attention for their practical applications due to their cost-effectiveness, thermal stability, selectivity, high activity, and wide availability. This review focuses on the synthesis and extensive applications of copper nanomaterials in environmental catalysis, addressing knowledge gaps in pollution management. It highlights recent advancements in using copper-based nanomaterials for the remediation of heavy metals, organic pollutants, pharmaceuticals, and other contaminants. Also, it will be helpful to young researchers in improving the suitability of implementing copper-based nanomaterials correctly to establish and achieve sustainable goals for environmental remediation.This work was supported by Qatar University through a National Capacity Building Program Grant (NCBP), [QUCP-CAM-20/23-463]. Statements made herein are solely the responsibility of the authors

Role of the intercalated ions on the high capacitance behavior of MXene nano-hybrids

Abstract[Formula: see text] (MXene) is prone to surface oxidation due to the presence of oxygen surface terminals in its surfaces. In this work, the effect of oxygen surface terminals has been reduced by replacing it with other surface terminals or thin layers of heteroatom at the interlayers. These resulted in increasing the interlayer spacing from 9.3 Å up to 12.5 Å with better flexibility properties, thereby facilitating electron/mass transports by exposing enough active surface areas. The carbon nano-plated MXene showed enhanced specific capacitance of 110 F/g at 2 mV/s in LiOH electrolytes for superior supercapacitors applications

Synthesis of yttrium doped BiOF/RGO composite for visible light: Photocatalytic applications

In this present work, yttrium doped bismuth oxy fluoride/reduced graphene oxide (Y-BiOF/RGO) composite was synthesized using a simple solvothermal method. As synthesized composite was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), photoluminescence spectroscopy (PL), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. The photocatalytic property was evaluated towards the degradation of methylene blue (MB) dye under the visible-light irradiation. The characterization results highlighted that the efficient incorporation of both yttrium ions and RGO greatly reduced the recombination rate of BiOF and extended the visible-light absorption ability. As synergistic effects, the prepared Y-BiOF/RGO composite exhibited maximum degradation rate of 98% in 360 min, which is 6.5 times higher than pure BiOF. The clear mechanism for the enhanced photo-activity by Y-BiOF/RGO was discussed. Keywords: BiOF, Graphene, Yttrium, Semiconductors, Visible light, Photocatalyst

Graphene-based membranes for CO2 separation

Increasing concentration of carbon dioxide (CO2) in the atmosphere is responsible for global warming in the world. Up to date, many technologies have been investigated to reduce the concentration of CO2 in the environment but no technology has got significant successes yet. Recently graphene based membrane has attracted increasing attention for their potential applications in gas separation. In this review, we focus on separation of CO2 from gas mixtures through graphene-based membranes. More specifically, the separation of gas mixtures such as CO2/H2, CO2/CH4, CO2/N2 and CO2/O2 which have similar compositions in flue gas treatment, hydrogen purification and natural gas purification will be discussed. The advantages and disadvantages of these membranes will also be part of discussion and finally, the review ends with several recommendations and suggestions on the future prospect for CO2 separation. Keywords: Carbon dioxide, Global warming, Graphene, Membrane, Separation, Purificatio

Direct cascade hydrogenation of biorenewable levulinic acid to valeric acid biofuel additives over metal (M = Nb, Ti, and Zr) supported SBA-15 catalysts

Chemoselective hydrogenation of biomass platform molecules into value-added chemicals and fuels is essential for the exploitation of biomass, and SBA-15 based metal catalysts with hydrogenation centers and acid sites seem promising in this regard. Valeric acid (VA) is the most important platform molecule for valeric biofuels and value-added chemicals production. The main issue with using such bifunctional catalysts for biomass conversion is maintaining the catalyst's stability in the liquid phase under harsh conditions. In-addition, direct one-pot selective hydrogenation of levulinic acid (LA) into VA synthesis is challenging due to its complex reaction conditions involved. Herein, we design a bifunctional mesoporous catalysts (SBA-15 mesoporous material doped with various metals Nb, Ti, and Zr) investigated for this reaction under the vapour phase. Different instrumental approaches were used to examine the structure, phase composition, morphology, and surface elemental analyses of catalysts as-prepared. Among those catalysts, Zr-doped mesoporous SBA-15 catalyst showed the 91% conversion of LA and the 68% selectivity toward VA and promising stability in a 52 h time on-stream run. Metal dispersion inside the SBA-15 and their surface acidity (sufficient number of acid sites and surface-active metal oxide species) and higher surface area are beneficial for the selectivity of VA. This work offers a highly-efficient bifunctional catalyst for selective hydrogenation of biomass feedstocks

Photocatalytic degradation of organic pollutant with nanosized cadmium sulfide

Efficient removal of organic pollutants from wastewater by using photocatalysis has become a hot research in recent days due to its ecological and environmental importance. Herein, cadmium sulfide (CdS) nanostructure with different morphologies i.e. nanoflowers and nanopetals were prepared by a hydrothermal method. The Structural properties of as-synthesized nanostructures material have been studied by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX), while UV–Visible spectroscopy have been used to study their optical properties. The photocatalytic activities of the prepared nanostructures have been evaluated by the photocatalytic degradation of organic dye i.e. rhodamine B (RhB). The highest degradation of 78% in CdS nanoflower and 63% in nanopetal for RhB was observed in 4 h. The EIS measurement showed that charge transfer resistance is lower in CdS nanoflower as compare to the nanopetal. The result showed that the CdS nanoflower was more active than nanopetal for photodegradation of RB dye due to more efficient charge transfer. Due to this excellent performance of CdS nanomaterials make it an ideal candidate for various engineering applications in near future. Keywords: Cadmium sulfide, Nanoflowers, Nanopetals, Photocatalytic degradation, Rhodamine