RESUMEN
The potential of tetra-penta-deca-hexagonal graphene (TPDH-gr), a recently proposed 2D carbon allotrope as an anodic material in lithium ion batteries (LIBs), was investigated through density functional theory calculations. The results indicate that Li-atom adsorption is moderate (around 0.70 eV), allowing for easy desorption. Moreover, energy barriers (0.08-0.20 eV), diffusion coefficient (>6 × 10-6 cm2/s), and open circuit voltage (0.29 V) calculations show rapid Li atom diffusion on the TPDH-gr surface, stable intercalation of lithium atoms, and good performance during the charge and discharge cycles of the LIB. These findings, combined with the intrinsic metallic nature of TPDH-gr, indicate that this new 2D carbon allotrope is a promising candidate for use as an anodic LIB material.
RESUMEN
Pesticides are crucial in modern agriculture because they reduce pests and boost yield, but they also represent major risks to human health and the environment; therefore, it is important to monitor their presence in food. Reliable and precise detection techniques are possible ways to address this issue. In this work, we utilize atomically thin (two-dimensional) cobalt telluride (CoTe2) with a high surface area and charge as a template material to detect mancozeb using spectroscopic and electrochemical techniques. When mancozeb (MNZ) molecules interact with 2D CoTe2, spectroscopic analyses reveal distinctive spectral shifts that clarify the underlying chemical interactions and binding mechanisms. Furthermore, CoTe2's electroactive sites and their manipulation for improved sensitivity and selectivity toward certain MNZ molecules are investigated by electrochemical studies. The CoTe2/GCE electrode exhibits enhanced electrochemical activity toward the electrooxidation of MNZ. The developed sensing electrode shows a linear range from 0.184 mM to 18.48 µM and a limit of detection of about 0.18 µM. In addition, we employ density functional theory (DFT) first-principles calculations to validate the experimental findings and comprehend the mechanism behind the interaction between CoTe2 and MNZ molecules. The study highlights the effectiveness of 2D CoTe2 as a dual-mode sensing platform for qualitative and quantitative assessment of MNZ pollutants, demonstrated by the integration of electrochemistry and spectroscopy and the critical role that 2D CoTe2-based sensors can play in accurate and efficient pesticide detection, which is required for agricultural safety protocols and environmental monitoring.
RESUMEN
This paper presents an ab initio investigation, performed in the framework of density functional theory, on the properties of functionalized few-layer silicene nanosheets, denoted as Si2X2 bilayers and Si4X2 trilayers with X = B, N, Al, and P. Searching for stable phases, we computed the structural, energetic, thermodynamic, dynamic, elastic, and electronic properties of those systems in several stacking configurations, labeled as AA', AB, AA'A'', and ABC. The results revealed that AA'-Si2N2, AB-Si2N2, AA'-Si2P2, and AB-Si2P2 bilayers, as well as ABC-Si4B2, ABC-Si4Al2, AA'A''-Si4P2, and ABC-Si4P2 trilayers are all dynamically stable, based on their respective phonon dispersion spectra. Particularly, there is scarce literature regarding functionalized trilayer silicene systems and, in this work, we found four new nanosheet systems with interesting physical properties and promising applications. Additionally, according to their standard enthalpies of formation and by exploring their electronic properties, we established that those structures could be experimentally accessed, and we discovered that those silicene nanosheets are indirect band gap semiconductors when functionalized with N or P atoms and metallic with B or Al ones. Finally, we envision potential applications for those nanosheets in alkali-metal ion batteries, van der Waals heterostructures, UV-light devices, and thermoelectric materials.