Electronic Properties of Triangle Molybdenum Disulfide (MoS2) Clusters with Different Sizes and Edges

Exploring the drug delivery capabilities of Nb2C MXene functionalized with oxygen and fluorine: A DFT study

MXenes quantum dots (QDs), including Nb2C, Nb2CO2, and Nb2CF2, are emerging materials with exceptional structural, electronic, and optical properties, making them highly suitable for biomedical applications. This study investigates the structural optimization, stability, electronic properties, and drug-loading potential of these QDs using fluorouracil (Flu) as a model drug. Structural analyses show that the functionalization of Nb2C with O and F atoms enhances stability, with binding energies (BEs) of 7.335, 8.154, and 6.704 eV for Nb2C, Nb2CO2, and Nb2CF2, respectively. The drug-loading study reveals that Nb2C exhibits the highest adsorption energy of -6.775 eV at the surface site (2.053 Å), while Nb2CO2 and Nb2CF2 demonstrate weaker interactions with adsorption energies of -2.163 eV and -0.933 eV, respectively. Non-covalent interaction (NCI) and natural bond orbital (NBO) analyses show significant changes in electron density distribution upon drug interaction, with the natural charge on the O7 atom in Flu shifting slightly upon interaction. Optical property investigations indicate a blue shift in the absorption spectra for Nb2CO2 (λmax = 764.76 nm) and Nb2CF2 (λmax = 1108.71 nm), compared to Nb2C (λmax = 2612.00 nm), confirming the tunability of these materials for therapeutic applications. By addressing key challenges in drug delivery, such as stability, controlled release, and interaction strength, this study establishes Nb2CO2 and Nb2CF2 as promising nanocarriers, with the potential to improve drug efficacy and minimize side effects in targeted cancer therapies.

Electronic and optical properties of chemically modified 2D GaAs nanoribbons

We employed density functional theory calculations to investigate the electronic and optical characteristics of finite GaAs nanoribbons (NRs). Our study encompasses chemical alterations including doping, functionalization, and complete passivation, aimed at tailoring NR properties. The structural stability of these NRs was affirmed by detecting real vibrational frequencies in infrared spectra, indicating dynamical stability. Positive binding energies further corroborated the robust formation of NRs. Analysis of doped GaAs nanoribbons revealed a diverse range of energy gaps (approximately 2.672 to 5.132 eV). The introduction of F atoms through passivation extended the gap to 5.132 eV, while Cu atoms introduced via edge doping reduced it to 2.672 eV. A density of states analysis indicated that As atom orbitals primarily contributed to occupied molecular orbitals, while Ga atom orbitals significantly influenced unoccupied states. This suggested As atoms as electron donors and Ga atoms as electron acceptors in potential interactions. We investigated excited-state electron-hole interactions through various indices, including electron-hole overlap and charge-transfer length. These insights enriched our understanding of these interactions. Notably, UV-Vis absorption spectra exhibited intriguing phenomena. Doping with Te, Cu, W, and Mo induced redshifts, while functionalization induced red/blue shifts in GaAs-34NR spectra. Passivation, functionalization, and doping collectively enhanced electrical conductivity, highlighting the potential for improving material properties. Among the compounds studied, GaAs-34NR-edg-Cu demonstrated the highest electrical conductivity, while GaAs-34NR displayed the lowest. In summary, our comprehensive investigation offers valuable insights into customizing GaAs nanoribbon characteristics, with promising implications for nanoelectronics and optoelectronics applications.

Electrodeposition of Molybdenum Disulfide (MoS2) Nanoparticles on Monocrystalline Silicon

Molybdenum disulfide (MoS2) has attracted great attention for its unique chemical and physical properties. The applications of this transition metal dichalcogenide (TMDC) range from supercapacitors to dye-sensitized solar cells, Li-ion batteries and catalysis. This work opens new routes toward the use of electrodeposition as an easy, scalable and cost-effective technique to perform the coupling of Si with molybdenum disulfide. MoS2 deposits were obtained on n-Si (100) electrodes by electrochemical deposition protocols working at room temperature and pressure, as opposed to the traditional vacuum-based techniques. The samples were characterized by X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Rutherford Back Scattering (RBS).