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MXenes have garnered significant attention for surface-enhanced Raman scattering (SERS) applications due to their exceptional electronic properties and remarkable hydrophilicity. However, niobium carbide (Nb2CTX), a notable member of the MXene family, has been underexplored for SERS applications. In this work, we present a comprehensive investigation of the SERS properties of Nb2CTx nanosheets, using methylene blue (MB) and crystal violet (CV) as probe molecules under laser excitations at 532 and 488 nm. The results revealed that the Raman enhancement of dye molecules on the Nb2CTx-based SERS substrate was determined by the interplay between laser energy and the probe molecule. The two orders of magnitude higher enhancement factor (EF) for MB (2.12 × 106) compared to CV (2.65 × 104) obtained using 532 nm laser excitation was attributed to a light-induced resonance charge transfer transition within the MB-Nb2CTX system. The distinctly different EF values for MB and CV suggest that SERS technology based on chemical mechanisms could enable selective molecular detection. Our results provide valuable insights into the SERS mechanism and contribute to the development of cost-effective and 2D MXene-based selective SERS substrates for molecular sensing applications. 

This review provides an overview of the fabrication methods for Ti3C2Tx MXene-based hybrid photocatalysts and evaluates their role in degrading organic dye pollutants. Ti3C2Tx MXene has emerged as a promising material for hybrid photocatalysts due to its high metallic conductivity, excellent hydrophilicity, strong molecular adsorption, and efficient charge transfer. These properties facilitate faster charge separation and minimize electron–hole recombination, leading to exceptional photodegradation performance, long-term stability, and significant attention in dye degradation applications. Ti3C2Tx MXene-based hybrid photocatalysts significantly improve dye degradation efficiency, as evidenced by higher percentage degradation and reduced degradation time compared to conventional semiconducting materials. This review also highlights computational techniques employed to assess and enhance the performance of Ti3C2Tx MXene-based hybrid photocatalysts for dye degradation. It identifies the challenges associated with Ti3C2Tx MXene-based hybrid photocatalyst research and proposes potential solutions, outlining future research directions to address these obstacles effectively. 

Abstract Bioactive degradable scaffolds that facilitate bone healing while fighting off initial bacterial infection have the potential to change established strategies of dealing with traumatic bone injuries. To achieve this a composite material made from calcium phosphate graphene (CaPG), and MXene was synthesized. CaPG was created by functionalizing graphene oxide with phosphate groups in the presence of CaBr with a Lewis acid catalyst. Through this transformation, Ca²⁺and PO₄³⁻inducerons are released as the material degrades thereby aiding in the process of osteogenesis. The 2D MXene sheets, which have shown to have antibacterial properties, were made by etching the Al from a layered Ti₃AlC₂(MAX phase) using HF. The hot‐pressed scaffolds made of these materials were designed to combat the possibility of infection during initial surgery and failure of osteogenesis to occur. These two failure modes account for a large percentage of issues that can arise during the treatment of traumatic bone injuries. These scaffolds were able to retain induceron‐eluting properties in various weight percentages and bring about osteogenesis with CaPG alone and 2 wt% MXene scaffolds demonstrating increased osteogenic activity as compared to no treatment. Additionally, added MXene provided antibacterial properties that could be seen at as little as 2 wt%. This CaPG and MXene composite provides a possible avenue for developing osteogenic, antibacterial materials for treating bone injuries. 

Two-dimensional (2D) molybdenum ditelluride (MoTe 2 ) is an interesting material for fundamental study and applications, due to its ability to exist in different polymorphs of 2H, 1T, and 1T′, their phase change behavior, and unique electronic properties. Although much progress has been made in the growth of high-quality flakes and films of 2H and 1T′-MoTe 2 phases, phase-selective growth of all three phases remains a huge challenge, due to the lack of enough information on their growth mechanism. Herein, we present a novel approach to growing films and geometrical-shaped few-layer flakes of 2D 2H-, 1T-, and 1T′-MoTe 2 by atmospheric-pressure chemical vapor deposition (APCVD) and present a thorough understanding of the phase-selective growth mechanism by employing the concept of thermodynamics and chemical kinetics involved in the growth processes. Our approach involves optimization of growth parameters and understanding using thermodynamical software, HSC Chemistry. A lattice strain-mediated mechanism has been proposed to explain the phase selective growth of 2D MoTe 2 , and different chemical kinetics-guided strategies have been developed to grow MoTe 2 flakes and films. 

Recently, a zipper two-dimensional (2D) material Bi 2 O 2 Se belonging to the layered bismuth oxychalcogenide (Bi 2 O 2 X: X = S, Se, Te) family, has emerged as an alternate candidate to van der Waals 2D materials for high-performance electronic and optoelectronic applications. This hints towards exploring the other members of the Bi 2 O 2 X family for their true potential and bismuth oxysulfide (Bi 2 O 2 S) could be the next member for such applications. Here, we demonstrate for the first time, the scalable room-temperature chemical synthesis and near-infrared (NIR) photodetection of ultrathin Bi 2 O 2 S nanosheets. The thickness of the freestanding nanosheets was around 2–3 nm with a lateral dimension of ∼80–100 nm. A solution-processed NIR photodetector was fabricated from ultrathin Bi 2 O 2 S nanosheets. The photodetector showed high performance, under 785 nm laser illumination, with a photoresponsivity of 4 A W −1 , an external quantum efficiency of 630%, and a normalized photocurrent-to-dark-current ratio of 1.3 × 10 10 per watt with a fast response time of 100 ms. Taken together, the findings suggest that Bi 2 O 2 S nanosheets could be a promising alternative 2D material for next-generation large-area flexible electronic and optoelectronic devices.