Indian Institute of Technology Ropar

PtS₂, a group-10 transition metal dichalcogenide (TMDC), has recently attracted enormous interest owing to its tunable band gap (0.25-1.6 eV), high carrier mobility, and large current on-off ratio of the devices. In contrast to other TMDCs, the growth of PtS₂ is more difficult, partly due to the nobility of Pt and partly due to the easier formation of the more stable PtS phase rather than PtS₂. Herein, we investigate the effect of critical growth parameters like sulfur amount, Pt thickness and gas flow rate for the control and large area growth of PtS₂ via thermal assisted conversion process in atm. chem. vapor deposition. The detailed characterization using Raman and XPS suggests a controlled transition from PtS to PtS₂, which can be obtained by fine tuning of these growth parameters. Furthermore, the optimized growth condition of PtS₂ is highly reproducible and can be grown on varieties of substrates like SiO₂/Si, sapphire, p-type Si, and even on flexible mica substrate. Finally, a high-performance PtS₂ photodetector (PD) was fabricated on different substrates. The PD fabricated on SiO₂/Si substrate with a detection range covering from visible to NIR region (400-1100 nm) showed a high responsivity and detectivity of 31.38 AW^-1 and 3.92 x 10¹³ Jones, resp., under 900 nm illumination at a low bias of 1 V. This work demonstrates an effective approach to control the growth of PtS₂ on varieties of substrate for high-performance next-generation photodetector for NIR photodetection applications.

Energy storage methods are cardinal for the mitigation of intermittency of renewable energy and among many technologies available, Li-ion batteries (LIBs) dominate the market on the account of their significant attributes. However, there is still room for improvement in their performance for high-end applications. Modifying the anode material can significantly affect the overall battery performance. It becomes necessary to discover a satisfactory neg. electrode for more productive Li ion batteries. The present d. functional theory based work examines the potential of a novel, exptl. fabricated 2D monolayer, Biphenylene having sp² carbon atoms arranged periodically in four, six, and eight-membered rings, for its application in LIBs as adequate anode. Phonon spectrum and ab initio mol. dynamics (AIMD) signify the dynamic and thermal stability of the nanosheet. The band structures and d. of states reveal the metallic nature which is maintained after the Li (adatom) adsorption as well. The mean adsorption energies for subsequent loading of Li over the sheet vary from -0.44 to -0.15 eV. The appreciative interactions between the adatom and the monolayer are well authenticated by charge transfer anal. The Biphenylene monolayer is observed to offer a low diffusion barrier of 0.23 eV for the Li atoms. High storage capacity of 1302 mAhg^-1 (almost 3.5 times higher than that of marketable Graphite), a low voltage of 0.34 V, and low volume changes (less than 3%) are noticed. This comprehensive study authenticates the capability of the 2D carbonous Biphenylene sheet as a suitable LIB neg. electrode.

The preconcentration of trace organic pollutants with low concentration in environmental water samples can be utilized as a significant approach to increase the sensitivity and accuracy of the particular detection system. Various nano-composite materials based on silver nanoparticles have proven potential for environment monitoring applications as they have cost-effectiveness and the highest quality factor in plasmonic ability in the spectrum from 300 to 1200 nm. In this context, herein, a short dipeptide was synthesized and thoroughly characterized by spectroscopic tools such as ¹H, ¹³ C NMR, FTIR, and ES-Mass spectrometry. Further, its organic nanoparticles (ONPs) were fabricated, and their nanocomposite with silver nanoparticles was prepared and validated by TEM, DLS, and UV-Visible spectroscopy. The developed ANS-H1 nanocomposite demonstrated selective colorimetric sensing of neomycin in water with a limit of detection of 70 pM. Further, the developed nanocomposite formed water-insoluble complexation with neomycin which constituted a rapid preconcentration step that may enhance sensing performance and brings the limit of detection (LOD) down to 23 pM. Thus, the present strategy for the selective detection of the trace organic pollutant neomycin possesses great potential for robust water quality for environment monitoring.