Transition metal carbides (TMCs) have recently emerged as competent members among the family of two-dimensional (2D) materials, owing to their promising applications. There are many promising applications of MXenes; however, their magnetic properties lack a wide margin, both experimentally as well as theoretically, which needs to be investigated for potential use in spintronics. In this study, we carried out a comprehensive etching process via selective extraction of Al layers from Nb₂AlC-MAX using a wet electrochemical route under well-optimized conditions to obtain fine 2D-Nb₂C MXene sheets. Structural analysis using X-ray diffraction (XRD) confirms the effective removal of Al followed by confirmation of a 2D layered structure from morphological analysis using scanning electron microscopy (SEM). Zero-field-cooled (ZFC) and field-cooled (FC) measurements of MAX and MXene at different field strengths were performed using a superconducting quantum interference device (SQUID). Magnetic measurements reveal the paramagnetic nature of Nb₂AlC-MAX measured under 5 mT; however, this changes to a clear superconductor-like diamagnetic behavior with a shift of the magnetization from positive to negative values at low temperatures when measured under 5 mT and 10 mT for Nb₂C MXene. The diamagnetism, however, is changed to paramagnetism at 100 mT, which shows the existence of critical fields known typically for a type-II superconductor. To gain an insight into this unusual behavior in MXene, density functional theory (DFT) first-principles calculation was also performed in Wein2K software using spin-polarized generalized gradient approximation (sp-GGA). The magnetic moment of the compound is calculated to be negative, which corresponds well with the experimental finding and suggests that the negative magnetic moment originated from the d-orbital of Nb₂C. The present report provides a pathway to deeply understanding the existence of superconductivity-like diamagnetic behavior in Nb₂C MXene, which is useful for future magnetic applications.

The green synthesis of nanoparticles has emerged as a cost-effective and environmentally benign technique. The present study describes the synthesis of silver nanoparticles (Ag-NPs) using a seed extract of Cydonia oblonga. The conditions were optimized by adjusting pH, temperature, time and amount of seed extract. The nanoparticles produced were characterized by different techniques, namely UV–visible spectroscopy, Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy. The formation of Ag-NPs was confirmed by UV–visible spectroscopic analysis. FTIR analysis was performed to identify the biomolecules, which played a key role in the reduction of Ag⁺ ions. XRD confirmed that the silver nanoparticles possessed face-centered cubic structure. The green chemistry approach has proven that Ag-NPs can be synthesized by using plant extract in which biomolecules effectively act as capping and reducing agent.

Nanosized metal nitrides, due to their chemical characteristics which make them sustainable alternatives to noble metals in catalysis, have drawn the attention of researchers worldwide. Transition metal nitrides are very similar in their method of synthesis, properties, and applications. Their synthetic parameters are considered to be the main factor for determining the effectiveness of metal nitrides in photocatalysis, energy storage devices, remediation of environmental pollutants, gas sensors, and biomedical applications. This review focuses on very recent advances made in synthetic approaches and electrocatalytic applications of metal nitrides. The synthetic approaches will provide an overview of cost of production and consumption of energy and time required for synthesis. Furthermore, some recent techniques that offer new paths for researchers, such as electrochemical, sol-gel, solvothermal, sonochemical, solid-state reaction, chemical synthesis, and many more, are also discussed. Various applications in electrocatalysis, water splitting, lithium ion batteries, and super-capacitors, etc. are summarized. We are confident that this review will provide very useful information for the upcoming community of researchers interested in synthesizing nitrides for various applications.