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Core‐shell Cu@Ag nanocatalyst have been synthesized via a two‐step thermal decomposition and galvanic displacement reaction. The nanocatalyst was intensively characterized by various analytical techniques. The formation of core‐shell nanoparticle (NPs) was initially confirmed by UV‐vis analysis followed by high resolution transmission electron microscopy (HRTEM) micrograph with Energy Dispersive X‐ray spectroscopy (EDS) mapping and line scan. This catalyst was found to be a highly efficient catalyst for the synthesis of octahydroquinazolinones. Compared with others, core‐shell nanoparticle of Cu@Ag shows better catalytic activity and much efficiency with high yield of product in less time. The higher activity of Cu@Ag core‐shell nanoparticles can be attributed to the increased oxidation stability of Cu nanoparticles by placing it in the core, lattice contraction and synergistic effect between the two metals. In this study, aromatic aldehydes with various functional groups were employed for the synthesis of octahydroquinazolinones. Later, the catalyst was found to be recyclable upto 5 cycles without any significant loss of activity. Our studies provide a platform for designing other potential core‐shell catalyst for the synthesis of biologically important fine chemicals.

Novel polymorphic Mo x W1–x Te2-based counter electrodes possess high carrier mobility, phase-dependent lattice distortion, and surface charge density wave to boost the charge-transfer kinetics and electrocatalytic activity in dye-sensitized solar cells (DSSCs). Here, we report the syntheses of stoichiometry-controlled binary and ternary Mo x W1–x Te2 nanowhiskers directly on carbon cloth (CC), denoted by Mo x W1–x Te2/CC, with an atmospheric chemical vapor deposition technique. The synthesized Mo x W1–x Te2/CC samples, including 1T′-MoTe2/CC, Td-WTe2/CC, Td-Mo0.26W0.73Te2.01/CC, and 1T′- & Td -Mo0.66W0.32Te2.02/CC, were then employed as different counter electrodes to study their electrochemical activities and efficiencies in DSSCs. The photovoltaic parameter analysis manifests that Mo x W1–x Te2/CCs are more stable than a standard Pt/CC in the I –/I 3 – electrolyte examined by cyclic voltammetry over 100 cycles. A 1T′- & Td -Mo0.66W0.32Te2.02/CC-based DSSC can achieve a photocurrent density of 16.29 mA cm–2, a maximum incident photon-to-electron conversion efficiency of 90% at 550 nm excitation, and an efficiency of 9.40%, as compared with 8.93% of the Pt/CC counterpart. Moreover, the 1T′- & Td -Mo0.66W0.32Te2.02/CC shows lower charge-transfer resistance (0.62 Ω cm2) than a standard Pt/CC (1.19 Ω cm2) in electrocatalytic reactions. Notably, Mo x W1–x Te2 nanowhiskers act as an electron expressway by shortening the path of carrier transportation in the axial direction from a counter electrode to electrolytic ions to enhance the reaction kinetics in DSSCs. This work demonstrates that the nanowhisker-structured 1T′- & Td -Mo0.66W0.32Te2.02/CC with high carrier mobility and robust surface states can serve as a highly efficient counter electrode in DSSCs to replace the conventional Pt counter electrode for electrocatalytic applications.

Near‐infrared light‐emitting technology is ideal for noncontact diagnostic medical imaging and high‐speed data communications. High‐quality ReSe2 nanosheets of anisotropic single‐crystal structure with a bandgap of 1.26 eV (≈984 nm) are synthesized with an atmospheric pressure chemical vapor deposition (APCVD) method. The as‐synthesized ReSe2 nanosheets‐fabricated light‐emitting transistors (LETs) exhibit nearly symmetric ambipolar characteristics in electrical transport. Judicious selection of asymmetric platinum (Pt)/chromium (Cr) electrodes, with their work functions matching respectively the conduction‐ and valence‐band edges of ambipolar ReSe2, generates a low turn‐on voltage ReSe2‐LET with the balanced number density and field‐effect mobility of bipolar carriers (i.e., electrons and holes). Room‐temperature near‐infrared electroluminescence (NIR EL) from the frequency‐modulated ReSe2‐LET has been observed unprecedentedly with the assistance of a lock‐in detection system. The NIR EL intensity is tested by varying the bias voltage applied to the ReSe2‐LET devices with different channel lengths. The wavelength of the NIR EL from ReSe2‐LET is differentiated with optical bandpass filters. Room‐temperature angle‐dependent two lobe‐shaped EL pattern manifests the inherent anisotropic in‐plane excitonic polarization of the ReSe2 crystal. The highly stable NIR EL from ReSe2‐LETs provides prospective 2D material‐based ultrathin scalable data communication electronics for future development.