Search

In this article, a high-performance nanostructured substrate has been fabricated for the ultrasensitive detection of the organic pollutant, Malachite green isothiocyanate (MGITC), in aquatic systems via the Surface Enhanced Raman Spectroscopy (SERS) technique. The chemical dealloying approach has been used to synthesize a three-dimensional nanoporous gold substrate (NPG) consisting of pores and multigrained ligament structures along thickness. The formation of the framework in NPG-5h has been confirmed by SEM with an average ligament size of 65 nm at the narrower neck. Remarkable SERS performance has been achieved by utilizing the NPG-5h substrate for the detection of MGITC, showing a signal enhancement of 7.9 × 109. The SERS substrate also demonstrated an impressively low-detection limit of 10−16 M. The presence of numerous active sites, as well as plasmonic hotspots on the nanoporous surface, can be accredited to the signal amplification via the Localized Surface Plasmon Resonance (LSPR) phenomenon. As a result, SERS detection technology with the fabricated-NPG substrate not only proves to be a simple and effective approach for detecting malachite green but also provides a basis for in situ detection approach of toxic chemicals in aquatic ecosystems.

The zeolitic imidazolate framework-67 (ZIF-67) adsorbent and its composites are known to effectively remove organic dyes from aqueous environments. Here, we report a unique crystalline MoS2@ZIF-67 nanocomposite adsorbent for the efficient removal of methyl orange (MO) dye from an aqueous medium. In situ synthetic techniques were used to fabricate a well-crystalline MoS2@ZIF-67 nanocomposite, which was then discovered to be a superior adsorbent to its constituents. The successful synthesis of the nanocomposite was confirmed using XRD, EDX, FTIR, and SEM. The MoS2@ZIF-67 nanocomposite exhibited faster adsorption kinetics and higher dye removal efficiency compared with its constituents. The adsorption kinetic data matched well with the pseudo-second-order model, which signifies that the MO adsorption on the nanocomposite is a chemically driven process. The Langmuir model successfully illustrated the MO dye adsorption on the nanocomposite through comparing the real data with adsorption isotherm models. However, it appears that the Freundlich adsorption isotherm model was also in competition with the Langmuir model. According to the acquired thermodynamics parameters, the adsorption of MO on the MoS2@ZIF-67 nanocomposite surface was determined to be spontaneous and exothermic. The findings of this research open an avenue for using the MoS2@ZIF-67 nanocomposite to efficiently remove organic dyes from wastewater efflux. [ABSTRACT FROM AUTHOR]

This, study reports ZIF-8 and its g-C3N4 based composites for successful adsorption of carbon dioxide gas at temperature of 45 °C and 0–15 bar pressure. These samples were characterized via using different techniques like XRD, EDX, SEM, FTIR to study the structural and morphological properties, The SEM results shows rougher and porous rhombic dodecahedron morphology, and the EDX analysis confirms that the catalyst production is free of impurities. The FTIR and XRD analyses show all the peaks and bands correspond to crystalline structure and necessary functional group presence in the prepared adsorbents. The ZIF-8 and its g-C3N4 composites have good adsorption capacity. Among them ZIF-8@3wt% g-C3N4 shows the highest adsorption capacity of 315 mg g−1 at 45 °C and 0–15 bar pressure. The rising adsorption trend of all prepared materials shows that these samples do not reach their saturation point and can still adsorb more CO2 even at a pressure higher than 15 bar. [ABSTRACT FROM AUTHOR]

Aqueous sodium-ion battery is a safe and efficient system for large-scale energy storage due to low cost, abundant sodium supply, non-flammable aqueous neutral electrolyte and quick charge–discharge performance. The use of fluoride-based material as electrode material has a certain advantage due to high potential window and energy density. Exploring perovskite materials has advantage of corner-sharing matrix structure which helps in easy ion and electron diffusion. Herein, we synthesized the perovskite-structured NaNiF3 and its composite with multi-walled carbon nanotubes (MWCNT) by a simple and cost-effective approach by the combination of precipitation and hydrothermal route. The synthesized material is characterized by X-rays diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and Brunauer–Emmett–Teller analysis. Electrochemical performance for aqueous sodium-ion batteries is tested by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy (EIS) in 1 M Na2SO4 electrolyte. XRD confirms the perovskite structure of NaNiF3 and NaNiF3 // MWCNT. SEM shows the orthorhombic cube and cubical structure of NaNiF3 and NaNiF3 // MWCNT. Electrochemical results demonstrate the excellent performance with a specific capacity of 33 mAh g−1 and 57 mAh g−1 at 0.1 A g−1 and shows excellent cyclic stability up to 500 cycles, indicating NaNiF3 // MWCNT as potential candidate among cathode material of aqueous sodium-ion battery. [ABSTRACT FROM AUTHOR]