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Recently, vanadium ditelluride (VTe2) a member of the transition metal ditellurdies family has emerged as a functional material for energy storage applications owing to its exotic intrinsic properties. Similar to most of the nanostructured materials, a hybrid structure of VTe2 is expected to provide enhanced energy storage capability. Herein, two hybrid structures of VTe2 are engineered using well‐explored nanocarbons such as RGO and carbon nanotube (CNT) to create a compelling supercapacitor electrode material. Both the hybrid structures show improved electrochemical activity, but VTe2/CNT fared better in the charge storage efficiency. The enhanced active sites, short ionic/electronic pathways provided by the CNT network, and the large electric double‐layer contribution have synergized for the inflated capacitance of VTe2/CNT. Further, a high‐performance asymmetric supercapacitor (ASC) of VTe2/CNT//MoSSe/CNT is constructed in a typical Swagelok cell, and the ASC delivered an energy density output of 36.28 Wh kg−1 at a power density of 463.16 W kg−1 with a remarkable 80.26% capacitance retention. The results of this work suggest that VTe2/CNT is a promising contender in the pantheon of functional materials for energy storage applications in the near future. [ABSTRACT FROM AUTHOR]

Borophene 2D nanosheets of boron and the evolving group III trans-graphene are a potential material for a plethora of applications; however, they have not been well explored due to the ambiguity in their electronic configuration and consequent polymorphism. Here, we introduced liquid-phase treatments utilizing surfactants exfoliating boron to 2D borophene. Poly-(ethelyene glycol) (PEG) polymeric chains with neutral characteristics simultaneously with surfactants of cationic and anionic characteristics, respectively, as cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were utilized to constructively engineer a β rhombohedral crystal structure in borophene layers. These engineered borophene layers, on further analyzing their electrochemical performance by hydrogen evolution reactions, showed a heightened efficacy for borophene sheets synthesized in the presence of PEG, characterized by a Tafel slope of 178 mV/dec in a 0.5 M H2SO4 solution. This enhanced performance was intricately linked to the elevated quality of the borophene sheets during PEG-assisted liquid-phase treatment and to the increased accessibility of active sites characterized by the β rhombohedral crystal lattices engineered by PEG polymeric chains. [ABSTRACT FROM AUTHOR]

Supercapacitors have emerged as a promising energy storage technology due to their high‐power density, fast charging/discharging capabilities, and long cycle life. Moreover, innovative electrode materials are extensively explored to enhance the performance, mainly the energy density of supercapacitors. Among the two‐dimensional (2D) supercapacitor electrodes, borocarbonitride (BCN) has sparked widespread curiosity owing to its exceptional tunable properties concerning the change in concentration of the constituent elements, along with an excellent alternative to graphene‐based electrodes. BCN, an advanced nanomaterial, possesses excellent electrical conductivity, chemical stability, and a large specific surface area. These factors contribute to supercapacitors' overall performance and reliability, making them a viable option to address the energy crisis. This review provides a detailed survey of BCN, its structural, electronic, chemical, magnetic, and mechanical properties, advanced synthesis methods, factors affecting the charge storage mechanism, and recent advances in BCN‐based supercapacitor electrodes. The review embarks on the scrupulous elaboration of ways to enhance the electrochemical properties of BCN through various innovative strategies followed by critical challenges and future perspectives. BCN, as an eminent electrode material, holds great potential to revolutionize the energy landscape and support the growing energy demands of the future. [ABSTRACT FROM AUTHOR]

Layered two-dimensional (2D) materials demonstrate exceptional performance as supercapacitor electrodes due to their unique intrinsic properties. A hybrid 2D/2D heterostructured electrode material can synergize the individual energy storage features of each of the layered 2D materials. Ti3C2 MXene is an emergent 2D material with enriched energy storage capabilities but suffers from certain vulnerabilities during the charge storage process. Vanadium ditelluride (VTe2) is an interesting yet unexplored layered material within the 2D transition metal dichalcogenide (TMD) family. Owing to the unique structural features, VTe2 showcases certain advantages in energy storage. The formation of the VTe2/Ti3C2 MXene heterostructure for energy storage applications has not been reported until now. Herein, we report a facile and simple hydrothermal synthesis approach to prepare bare VTe2 and the VTe2/MXene heterostructure for supercapacitor applications. The energy storage mechanism in the heterostructure is systematically analyzed. The synergistically induced interplaying effects enhance the specific capacitance of the heterostructure to 250 F g−1 along with excellent durability during long cycle operation. Consequently, an asymmetric system is constructed with VTe2/MXene as the positive electrode and MoS2/MXene as the negative electrode. The 2D/2D heterostructure-based asymmetric supercapacitor delivers excellent performance with an energy density of 46.3 W h kg−1 and a highest power density of 6400 W kg−1. Furthermore, the density functional theory calculations predict that the enhancement of electronic Te 5P states near the Fermi level due to MXene leads to improved performance of the VTe2/Ti3C2 hybrid for supercapacitor applications. [ABSTRACT FROM AUTHOR]

MXene-based hybrid materials have been expedited extensively for supercapacitors and energy storage applications. In this work, we have grown the metallic VSe2 layered material on MXene sheets to achieve enhanced energy storage performance. The VSe2/MXene heterostructures showed improved energy storage performance with a specific capacitance of 144 F/g at a specific current of 1 A/g and a cycling life of 92.8% after 5000 charge-discharge cycles in a two-electrode symmetric configuration. Further, we have presented extensive density functional theory simulations to study the bonding interaction and electronic properties of VSe2 and its hybrid VSe2/MXene. The enhanced states near the Fermi level, superior quantum capacitance, and lower diffusion barrier of hybrid VSe2/MXene over the VSe2 support the improved charge storage and better capacitive behavior of the hybrid, as indicated by experimental observations. The interaction between VSe2 and the MXene is due to the electronic charge transfer from the Ti 3d orbital of the MXene to V 3d orbital of VSe2, in addition to weak van der Waals forces. An asymmetric supercapacitor was also constructed to exploit the high energy storage performance of the VSe2/MXene electrode. Further, the VSe2/MXene//MoS2/MWCNT asymmetric electrode assembly delivered an energy density of 42 W h/kg at power density of 2316 W/kg with a capacitance retention of 90% after 5000 charge-discharge cycles. [ABSTRACT FROM AUTHOR]

Excellent cyclic stability and fast charge/discharge capacity demonstrated by supercapacitors foster research interest into new electrode materials with 100% cycle life and high specific capacitance. We report an improvement in the electrochemical performance of MoS2/multiwalled carbon nanotubes (MWCNT) nanohybrid and intensively explored its performance in symmetric and asymmetric supercapacitor (ASC) assembly. The symmetric assembly of MoS2/MWCNT exhibits capacitance of around 274.63 F g−1 at 2 A g−1 with higher specific energy/power outputs (20.70 Wh kg−1/1.49 kW kg−1) as compared to the supercapacitor based on pristine MoS2 (5.82 Wh kg−1/1.07 kW kg−1). On the other hand, a unique all-carbon-based ASC assembled with MoS2/MWCNT and VSe2/MWCNT composite with K2SO4 as electrolyte delivers the highest energy density of 32.18 Wh kg−1 at a power density of 1.121 kW kg−1 with exceptional cycling stability and excellent retention of about 98.43% even after 5000 cycles. These outstanding results demonstrate the excellent electrochemical properties of both symmetric and asymmetric systems with high energy density and performance, which further enable them to be a potential candidate for supercapacitor applications. [ABSTRACT FROM AUTHOR]

The research interest in wearable sensors has tremendously increased in recent years. Amid the different biosensors, electrochemical biosensors are unparalleled and ideal for the design and manufacture of such flexible and wearable sensors because of their various benefits, including convenient operation, quick response, portability, and inherent miniaturization. A number of studies on flexible and wearable electrochemical biosensors have been reported in recent years for invasive/non-invasive and real-time monitoring of biologically relevant molecules such as glucose, lactate, dopamine, cortisol, and antigens. To attain this, novel two-dimensional nanomaterials and their hybrids, various substrates, and detection methods have been explored to fabricate flexible conductive platforms that can be used to develop flexible electrochemical biosensors. In particular, there are many advantages associated with the advent of two-dimensional materials, such as light weight, high stretchability, high performance, and excellent biocompatibility, which offer new opportunities to improve the performance of wearable electrochemical sensors. Therefore, it is urgently required to study wearable/flexible electrochemical biosensors based on two-dimensional nanomaterials for health care monitoring and clinical analysis. In this review, we described recently reported flexible electrochemical biosensors based on two-dimensional nanomaterials. We classified them into specific groups, including enzymatic/non-enzymatic biosensors and affinity biosensors (immunosensors), recent developments in flexible electrochemical immunosensors based on polymer and plastic substrates to monitor biologically relevant molecules. This review will discuss perspectives on flexible electrochemical biosensors based on two-dimensional materials for the clinical analysis and wearable biosensing devices, as well as the limitations and prospects of the these electrochemical flexible/wearable biosensors. Graphical abstract [ABSTRACT FROM AUTHOR]

Borophene stands out uniquely among Xenes with its metallic character, Dirac nature, exceptional electron mobility, thermal conductivity, and Young's moduli—surpassing graphene. Invented in 2015, various methods, including atomic layer deposition, molecular beam epitaxy, and chemical vapor deposition, have successfully been demonstrated to realize substrate-supported crystal growth. Top-down approaches like micromechanical, sonochemical, solvothermal and modified hummer's techniques have also been employed. Thanks to its high electronic mobility, borophene serves as an active material for ultrafast sensing of light, gases, molecules, and strain. Its metallic behaviour, electrochemical activity, and anti-corrosive nature make it ideal for applications in energy storage and catalysis. It has been proven effective as an electrocatalyst for HER, OER, water splitting, CO 2 reduction, and NH 3 reduction reactions. Beyond this, borophene has found utility in bioimaging, biosensing, and various biomedical applications. A special emphasis will be given on the borophene nanoarchitectonics i.e. doped borophene and borophene-based hybrids with other 2D materials and nanoparticles and the theoretical understanding of these emerging materials systems to gain more insights on their electronic structure and properties, aiming to manipulate borophene for tailored applications. [ABSTRACT FROM AUTHOR]

MXenes with distinctive structures, good electrical conductivity and abundant functional groups have shown great potential in the fabrication of high performance gas sensors. Since the sensing mechanism of MXene-based gas sensors often involves a surface-dominant process, they can work at room temperature. In this regard, a significant amount of research has been carried out on MXene-based room temperature gas sensors and they can be viewed as one of the possible materials for NO 2 sensing applications in the future. In this review, we focus on the most recent research and improvements in pure MXenes and their nanocomposites for NO 2 gas sensing applications. First, we have explored the mechanisms involved in MXenes for NO 2 gas sensing. Following that, other ways to tune the MXene sensing performance are investigated, including nanocomposite formation with metal oxides, polymers, and other 2D materials. A comparative analysis of the RT NO 2 sensor performance based on MXenes and their hybrids is provided. We also discuss the major challenges of using MXene-related materials and the areas that can further advance in the future for the development of high-performance room temperature NO 2 gas sensors., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)