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Oil spilled during transportation, domestic, and industrial usage causes grave water and soil pollution. Therefore, oil recovery through absorption or separation from water has been a challenge to the scientific community. The 3D porous structure of polyurethane (PU) sponge attracted significant attention in oil-water separation applications. However, its poor hydrophobicity decreases and limits its oil-absorption efficacy dramatically. In this paper, we focused on improving the hydrophobicity of the sponge by modifying it with graphene oxide (GO) followed by its reduction to reduce graphene oxide (rGO) via a commonly available green reducing agent, L-ascorbic acid (L-AA). The rGO modified PU sponge was used to absorb and collect oil from an oil-water mixture with satisfactory recoveries of up to ~ 97%. Moreover, the prepared rGO-PU sponge exhibited excellent reusability and compressibility without any crack or leaking. Finally, we compared the results of this study with rGO modified cotton (rGO-cotton) surfaces prepared via the same protocols. The results show that the high compressible and porous nature of sponges (rGO-PU) outperformed the rGO-cotton. Furthermore, this research work was proven to be environmentally friendly and cost-effective absorbent for efficiently extracting oil from oil-water mixtures with fewer toxic chemicals and cheap raw materials utilization. [ABSTRACT FROM AUTHOR]

The present study demonstrates the thermal stability and photocatalytic activity of TiO2-based nanotubes with respect to post-hydrothermal treatment. Titanate nanotubes were synthesized by adapting an alkali hydrothermal method from TiO2 sol using NaOH as a catalyst. The effect of post-hydrothermal heating on the properties—such as structure, morphology, textural properties, and activity—of as-synthesized one-dimensional titania nanostructure is investigated in detail. The characterizations are carried out using SEM, EDX, TEM, XRD, and a BET surface area analyzer. When heated in the presence of water in an autoclave, the protonated titanate phase of the nanotubes converts to anatase phase. Meanwhile, the tubular morphology is gradually lost as the post-hydrothermal heating duration increases. The photocatalytic activity was assessed utilizing the photo-oxidation of an amaranth dye. It is discerned that the as-prepared nanotubes are photocatalytically inactive but become active after post-hydrothermal processing. The activity trend follows the formation of the active phase—the titanate phase crystallizes into a photocatalytically-active anatase phase during post-hydrothermal heating. The effect of experimental parameters, such as reaction pH, dye concentration, and amount of catalyst, on the dye removal is studied. The findings also highlight that the role of holes/OH• is more prominent as compared to conduction band electron/O2−• for the removal of the dye. In addition, the photocatalyst exhibited excellent stability and reusability. [ABSTRACT FROM AUTHOR]

MXene, a novel class of 2-dimensional transition metal carbides has evolved as a promising material for various applications owing to its outstanding characteristics such as hydrophilicity, high electrical conductivity, surface area, and attractive topological structure. MXenes can form dispersion in common solvents and constitute composite with other nanomaterials, which can be utilized as effective transducers for molecular sensing. MXene-modified support materials, thus provide an intriguing platform for immobilization of target molecules onto their surface. The literature reveals that it has been increasingly utilized in the sensing of diverse types of analytes including glucose, pharmaceuticals, metals and dyes, cancer markers, pesticides, neurotransmitters, small valuable molecules, and so on. In this review, we summarize the recent updates in the MXene modified materials for sensing. For the convenience of our audience, we have distributed the analytes into categories and discussed them comprehensively. Not only we present the synthesis approach, electrochemical properties and surface chemistry of MXenes but also discussed briefly the current challenges and an outlook for future research in the related area. [ABSTRACT FROM AUTHOR]

Microbial contaminations and infections are hazardous and pose crucial concerns for humans. They result in severe morbidity and mortality around the globe. Even though dish-culturing, polymerase chain reaction (PCR), an enzyme-linked immunosorbent assay (ELISA) exhibits accurate and reliable detection of bacteria but these methods are time-consuming, laborious, and expensive. This warrants early detection and quantification of bacteria for timely diagnosis and treatment. Bacteria imprinting ensures a solution for selective and early detection of bacteria by snagging them inside their imprinted cavities. This review provides an insight into MIPs based bacterial detection strategies, challenges, and future perspectives. [ABSTRACT FROM AUTHOR]

In this work, a simple and facile method was developed to achieve controlled oxidation and enhance the surface area of MXene nanosheets and their utilization in the efficient sensing of ascorbic acid (AA or vitamin C). After etching of MAX phase to MXene via the MILD technique, controlled flash oxidation was carried out in the open air environment for 1.5 h, followed by flocculation of oxidized MXene nanosheets by using H 2 SO 4 , consequently achieving crumpled MXene possessing anatase phase, porosity, and improved surface area as revealed and confirmed by SEM, TEM, Raman, and BET analysis results. The as-prepared crumpled MXene was coated over a glassy carbon electrode (GCE) and used to determine AA successfully via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) with a linear concentration range of 300 μM to 0.005 μM with a detection limit (LOD) of 2 nM (2.8 % RSD and S/N = 3). The developed electrochemical sensor was used to determine the AA in various actual samples such as juice, urine, serum, and erythrocytes spiked with AA with excellent recoveries in the 94–103 % range. The sensor also demonstrated excellent reproducibility (~1 % RSD for five repetitive assays) and a shelf life of nearly one month with a negligible decrease in response. Furthermore, it lost only 10 % of its response for the next ten days. It also showed satisfactory selectivity toward AA in the presence of other similar compounds, including uric acid (UA), dopamine (DA), and glucose. [ABSTRACT FROM AUTHOR]

MXenes, 2-dimensional (2D) layered materials, have been able to garner immense popularity among researchers and academia alike in recent times. MXenes are typically produced from the selective etching of "A" group metal layer using an etchant (usually HF) from the parent MAX phase structure where M represents a metal from early transition metals. Their unique surface chemistry and intriguing electrochemical behavior, combined with their high biocompatibility, make them ideal as a support matrix for the development of cutting-edge electrochemical energy storage, biomedicine, electrochemical sensing, and biosensing devices. Due to the surging demand for batteries that can enable recent technological advancements such as electric vehicles to reach their full potential, the high specific capacitance and outstanding electrochemical energy storage of MXenes are under extensive research in recent times. Ti-based MXene has shown tremendous potential and thus many excellent reviews appeared around it and other MXenes in general. However, there are not many specialized reviews for other types of MXenes. Herein, we reviewed the current research advances, challenges, and prospects of the three most popular MXenes: Niobium (Nb), Vanadium (V), and Molybdenum (Mo) based MXenes. The applications of each form of MXene have been divided into categories for the reader's convenience. Finally, we have highlighted the challenges and future perspectives. [ABSTRACT FROM AUTHOR]

AbstractMolecularly imprinted polymer (MIP)-based electrochemical sensors have been extensively researched due to their higher sensitivity, quick response, and operational ease. To develop more advanced sensing devices with enhanced properties, MIPs have been integrated with two-dimensional (2D) layered materials such as transition metal dichalcogenides (TMDs) and MXenes. These 2D materials have unique electronic properties and an extended surface area, making them promising sensing materials that can improve the performance of MIPs. In this review article, we describe the methods used for the synthesis of TMDs and MXenes integrated MIP-based electrochemical sensors. Furthermore, we have provided a critical review of a wide range of analytes determined through the application of these electrochemical sensors. We also go over the influence of TMDs and MXenes on the binding kinetics and adsorption capacity which has enhanced binding recognition and sensing abilities. The combination of TMDs and MXenes with MIPs shows promising synergy in the development of highly efficient recognition materials. In the future, these sensors could be explored for a wider range of applications in environmental remediation, drug delivery, energy storage, and more. Finally, we address the challenges and future perspectives of using TMDs and MXenes integrated MIPs. We conclude with a focus on future development and the scope of integrating these materials in sensing technology. [ABSTRACT FROM AUTHOR]

Developing high-performing and scalable electrode materials for supercapacitors and batteries has been of tremendous interest for the world's forthcoming clean and renewable energy transition. As a versatile material, Two-dimensional graphitic carbon nitride (g-CN) has been utilized in electrochemical energy storage (EES) applications due to its nitrogen-rich adsorption sites, cost-effective production, and tunable electronic structure. The electrochemical performance of pristine g-CN has been boosted by forming hybrid architectures with highly conductive carbon-based materials, such as graphene, reduced graphene oxide, carbon nanofibers, carbon nanotubes, and beyond (e.g., MXene). Using such heterogeneous compositions for EES applications has significantly increased in recent years. This study reviews the g-CN/carbon nanomaterial (CNM) hybrids, considering the dimensionality in nanomaterials, and underscores the influence of the material's dimensionality and the synthesis/fabrication routes. The effect of structural and physicochemical changes on the electrode's electrochemical performance after hybridization is presented comparatively. Besides, the comprehensive review outlines challenges and future improvements in g-CN/CNM hybrid materials for outstanding developments in energy storage systems. [Display omitted] • Graphitic carbon nitride (g-CN)/carbon nanomaterial (CNM) hybrids are reviewed for supercapacitor and battery applications. • The impact of the CNM-type on the hybrid electrode's performance is examined through a chemical and physical perspective. • An overview of how hybrid electrode synthesis affects ion/electron transport, surface area, and porosity is provided. • Design-oriented control of the physicochemical properties for enhanced electrochemical performance is exemplified. • g-CN/CNM nanoarchitectures are emphasized as electrode materials with the potential for easy scalability. [ABSTRACT FROM AUTHOR]

This study aimed to synthesize highly reactive ZrO 2 nanoparticles using a straightforward sol-gel method for addressing water contamination from hazardous metal ions and organic dyes. Structural and photocatalytic properties were assessed using X-ray diffraction (XRD), Fourier transmission Infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and UV–visible absorption spectroscopy. XRD analysis confirmed the tetragonal crystal structure of ZrO 2. Photodegradation experiments using Eriochrome Black T (EBT) as a model dye revealed nearly 99% degradation under natural sunlight. Investigations into catalyst loading, dye concentration, pH, and irradiation source were conducted. Preliminary tests demonstrated the adsorbent's efficacy in removing Ca2+ ions. Further process optimizations could significantly enhance the potential of this innovative adsorbent for extracting metal ions from complex effluents. • Investigating the degradation of dyes in wastewater through photodegradation studies. • Tunning the morphology of nanocomposites to tackle difficult dye degradation scenarios. • Exploration of creating, analyzing, and potential uses of ZrO 2 nanoparticles. • Efficient elimination of heavy metal ion pollutants. [ABSTRACT FROM AUTHOR]

Despite their high analytical performance, conventional analytical biosensor devices are usually difficult to handle, time-consuming, bulky and expensive. As a result, their applications remain restricted to resource-limited environments. In particular, the transportation of conventional analytical equipment is challenging for the proper in-situ point of need (PON)/point of care (POC) detection of biomolecules. In this context, smartphones, the most widely utilized cutting-edge mobile gadgets, continue to be a favored option because of their ease of portability and revolutionary sensing capabilities. On the other hand, aptamers are molecular recognition units consisting of nucleic acids with highly sensitive and selective recognition capabilities towards their respective targets. The coupling of smartphones with aptamers have led the development of advanced, user-friendly, portable, and cost-effective in-situ PON/POC biosensors for the detection of biomolecules. Such sensors are well-suited for a variety of applications, including food safety, environmental monitoring, and disease diagnostics. Herein, for the first time, achievements made between 2017 and 2022 in the concept and design of the smartphone-enabled aptasensors for biosensing applications are reviewed. The review covers different fabrication strategies and the discussion of several operating systems, underlying programs, and related software. At the end, the important merits, challenges, and future prospects of smart phone-driven aptasensors are presented. This report intends to assist scientists and engineers in comprehending the fabrication of smartphone-based aptasensors and their underlying sensing principles, as well as stimulating the future developments in the direction of affordable, portable, simple, and readily available sensing devices. • The smartphone-based aptasensors facilitate advanced, user-friendly, portable, and cost-effective PON and POC biosensing. • Smartphone-enabled aptasensors are well-suited for applications in food safety, environmental monitoring, and disease diagnostics. • Fabrication strategies, working mechanisms, underlying operating systems, and related hardware/software have been reviewed. • Advantages, challenges and future outlook of smartphone-based aptasensors have been discussed. [ABSTRACT FROM AUTHOR]