Engineering of 2D transition metal carbides and nitrides MXenes for cancer therapeutics and diagnostics.

The 2D layered structured material with unique surface terminations and properties have showed great potential in variety of biomedical research fields including drug delivery and cancer therapeutics which forms the major focus of this review. MXenes as a multifunctional two-dimensional (2D) nanomaterial, has also received momentous research interest in oncology resulting from its intriguing structure and fascinating properties of magnetism and photodynamic properties such as luminescent, conductivity, magnetism, non-toxicity and its bio compatibility. This reported review intends to cover exclusively the synthesis and utilization of MXenes in oncological applications, and subsequently its future outlook in cancer therapeutic, diagnostic and theranostics. The versatile and unique physio-chemistry of MXenes permits fine tuning of its properties towards oncological applications ranging from the cancer therapeutic (e.g., photothermal therapy, photodynamic therapy, radiation therapy, chemotherapy) to cancer imaging (e.g., CT/MRI/PA imaging) as well as cancer theranostic applications. We have started the discussion by portraying the broad picture of physio-chemical aspects of MXenes followed by its drug delivery functionalities. Subsequently, ROS mediated therapeutic strategies of photodynamic therapy and radiotherapy as well as light triggered functionalities of MXenes were detailed comprehensively. In the middle of the gallery, various imaging and sensing aspects of MXenes were elucidated. Finally, we have concluded by explaining the combined therapy and diagnostic functions (theranostics) of MXenes. To put it in perspective, the current challenges and new opportunities in MXenes also discussed will give great realistic insights to motivate further research in realizing MXene as an intelligent oncological tool.

Hybrid carbon nanostructured fibers: stepping stone for intelligent textile-based electronics.

The journey of smart textile-based wearable technologies first started with the attachment of sensors to fabrics, followed by embedding sensors in apparels. Presently, garments themselves can be transformed into sensors, which demonstrates the tremendous growth in the field of smart textiles. Wearable applications demand flexible materials that can withstand deformation for their practical use on par with conventional textiles. To address this, we explore the potential reasons for the enhanced performance of wearable devices realized from the fabrication of carbon nanostructured fibers with the use of graphene, carbon nanotubes and other two-dimensional materials. This review presents a brief introduction on the fabrication strategies to form carbon-based fibers and the relationship between their properties and characteristics of the resulting materials. The likely mechanisms of fiber-based electronic and storage devices, focusing mainly on transistors, nano-generators, solar cells, supercapacitors, batteries, sensors and therapeutic devices are also presented. Finally, the future perspectives of this research field of flexible and wearable electronics are discussed. The present study supplements novel ideas not only for beginners aiming to work in this booming area, but also for researchers actively engaged in the field of fiber-based electronics, dealing with advanced electronics and wide range of functionalities integrated into textile fibers.

Fluorination-Enhanced Ambient Stability and Electronic Tolerance of Black Phosphorus Quantum Dots.

The environmental instability and uneliminable electronic trap states in black phosphorus quantum dots (BPQDs) limit the optoelectronics and related applications of BPQDs. Here, fluorinated BPQDs (F-BPQDs) are successfully synthesized by using a facile electrochemical exfoliation and synchronous fluorination method. The F-BPQDs exhibit robust ambient stability and limited fluorination capability, showing a nonstoichiometric fluorination degree (DF) maximum of ≈0.68. Density functional theory calculations confirm that due to the edge etching effect of fluorine adatoms, the simulated F-BPQDs become structurally unstable when DF surpasses the limit. Furthermore, the trap states of BPQDs can be effectively eliminated via fluorination to obtain a coordination number of 3 or 5 for fluorinated and unfluorinated phosphorus atoms. The results reveal that the air-stable F-BPQDs exhibit fluorine defect-enhanced electronic tolerance, which is crucial for nanophotonics and nanoelectronics applications.

Emerging Trends in Phosphorene Fabrication towards Next Generation Devices.

The challenge of science and technology is to design and make materials that will dominate the future of our society. In this context, black phosphorus has emerged as a new, intriguing two-dimensional (2D) material, together with its monolayer, which is referred to as phosphorene. The exploration of this new 2D material demands various fabrication methods to achieve potential applications- this demand motivated this review. This article is aimed at supplementing the concrete understanding of existing phosphorene fabrication techniques, which forms the foundation for a variety of applications. Here, the major issue of the degradation encountered in realizing devices based on few-layered black phosphorus and phosphorene is reviewed. The prospects of phosphorene in future research are also described by discussing its significance and explaining ways to advance state-of-art of phosphorene-based devices. In addition, a detailed presentation on the demand for future studies to promote well-systemized fabrication methods towards large-area, high-yield and perfectly protected phosphorene for the development of reliable devices in optoelectronic applications and other areas is offered.

Photonics and optoelectronics of two-dimensional materials beyond graphene.

Apart from conventional materials, the study of two-dimensional (2D) materials has emerged as a significant field of study for a variety of applications. Graphene-like 2D materials are important elements of potential optoelectronics applications due to their exceptional electronic and optical properties. The processing of these materials towards the realization of devices has been one of the main motivations for the recent development of photonics and optoelectronics. The recent progress in photonic devices based on graphene-like 2D materials, especially topological insulators (TIs) and transition metal dichalcogenides (TMDs) with the methodology level discussions from the viewpoint of state-of-the-art designs in device geometry and materials are detailed in this review. We have started the article with an overview of the electronic properties and continued by highlighting their linear and nonlinear optical properties. The production of TIs and TMDs by different methods is detailed. The following main applications focused towards device fabrication are elaborated: (1) photodetectors, (2) photovoltaic devices, (3) light-emitting devices, (4) flexible devices and (5) laser applications. The possibility of employing these 2D materials in different fields is also suggested based on their properties in the prospective part. This review will not only greatly complement the detailed knowledge of the device physics of these materials, but also provide contemporary perception for the researchers who wish to consider these materials for various applications by following the path of graphene.

Present perspectives of broadband photodetectors based on nanobelts, nanoribbons, nanosheets and the emerging 2D materials.

Recent research on photodetectors has been mainly focused on nanostructured materials that form the building blocks of device fabrication. The selection of a suitable material with well-defined properties forms the key issue for the fabrication of photodetectors that cover different ranges of the electromagnetic spectrum. In this review, the latest progress in light detection using nanobelts, nanoribbons, nanosheets and the emerging two-dimensional (2D) materials is reviewed. Particular emphasis is placed on the detection of light by the hybrid structures of the mentioned nanostructured materials in order to enhance the efficiency of the light-matter interaction. The booming research area of black phosphorus based photo-detection is also reviewed. This review provides an overview of basic concepts and new directions towards photodetectors, and highlights potential for the future development of high performance broadband photodetectors.

Carbon-doped SiO(x) nanowires with a large yield of white emission.

The growth of SiOx nanowires (NWs) with intense white emission is reported. Due to carbon monoxide gas being used as a dopant precursor, carbon-doped under-stoichiometric silicon dioxide NWs are obtained. The doping of the NWs is studied by means of x-ray photoelectron spectroscopy, which allows to assess the presence of carbon atoms in the silicon oxide amorphous structure. The light emission properties are studied by means of cathodoluminescence spectroscopy, which shows three main emission bands set at 2.7 eV (blue), 2.3 eV (green) and 1.9 eV (red), resulting in the white emission.