The sandwich-like 2H MoS2 and unilaminar graphitic nanocarbon hybrid was synthesized via graphitizing threonic acid intercalated MoS2 precursor obtained using hydrothermal process. An excellent electrocatalytic efficiency of hydrogen evolution reaction with a remarkably small overpotential of 195 mV and a Tafel slope of 47 mV/decade is easily accessible for our hybridized catalyst in 0.5 M H2SO4 aqueous solution, much superior to that of pure 2H MoS2 and threonic acid intercalating MoS2 nanomaterials. Moreover, the detailed electrochemical activity surface area and electrochemical impedance suggest that the face-to-face stacking of unilaminar 2H MoS2 and graphitic nanocarbon at an alternating sequence accelerates the mass transport and electron transfer and, thus, enhances the efficiency for electrocatalytic water splitting. This work paves a neoteric and straightforward pathway for the fabrication of superlattice MoS2 and unilaminar graphitic nanocarbon hybrid, further improving the electrocatalytic efficiency of 2H MoS2 nanosheets via a synergistic modulation strategy.

Group I−III−VI 2 semiconductors are promising for the fabrication of electronic and photoelectronic devices because of their tunable band gaps and intensive absorption in visible and near-infrared regions. Here, ternary AgInTe 2 nanostructures have been synthesized via a facilely designed solution-phase procedure at 240−280 °C from AgNO 3 and In(acac) 3 in oleylamine reacted with TeO 2 dissolved in 1-dodecanethiol. They illustrate truncated quasitetrahedrally geometrical shapes from the phosphine-free solution synthetic route and could be spin-coated on silicon wafer to set up a vertical AgInTe 2 /Si heterojunction-based photodetector. The device is highly sensitive to visible and near-infrared illuminance and has remarkable photoresponsive properties with an on/off switch ratio of 780 at a reverse bias of −5 V, a high responsivity (2.82 A W −1 ), specific detectivity (8.12 × 10 11 Jones), and a low noise equivalent power (2.46 × 10 −13 W Hz −1/2 ) at a bias of −2 V. Especially, the device exhibits fast response speeds (τ rise = 5.2 μs, τ fall = 18.4 μs), which would be a vital figure of merit for its technical application. The present work offers an available strategy for the tunable synthesis of ternary and even multiple-component tellurides beyond the demonstrated high-quality AgInTe 2 nanostructures and would provide a simplified way to heterostructure-based photodetectors with high-responsivity and fast-speed performances. KEYWORDS: group I−III−VI 2 semiconductor, chalcopyrite-type telluride, monodisperse AgInTe 2 nanocrystals for broadband photodetection, AgInTe 2 -based photodetector, fast-response photodetector

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Manganese-based chalcogenides would be of latent capacity in serving as anodes for assembling lithium- and/or sodium-ion batteries (LIBs/SIBs) due to their large theoretical capacity, low price, and low-toxicity functionality, while the low electroconductivity and easy agglomeration behavior may impede their technical applications. Here, a solid-state solution of MnS0.5Se0.5 nanocubes in rock-salt phase has been synthesized for the first time at a relatively low temperature from the precursors of Mn­(II) acetylacetonate with dibenzyl dichalcogens in oleylamine with octadecene, and the MnS0.5Se0.5 nanocubes have been assembled with N-doped graphene to form a new kind of heterostructured nanohybrids (shortened as MnS0.5Se0.5/N-G hybrids), which are very potential for the fabrication of metal-ion batteries including LIBs and/or SIBs. Investigations revealed that there have been dense vacancies generated and active sites increased via nonequilibrium alloying of MnS and MnSe into the solid-solution MnS0.5Se0.5 nanocubes with segregation and defects achieved in the low-temperature solution synthetic route. Meanwhile, the introduction of N-doped graphene forming heterojunction interfaces between MnS0.5Se0.5 and N-doped graphene would efficiently enhance their electroconductivity and avoid agglomeration of the active MnS0.5Se0.5 nanocubes with considerably improved electrochemical properties. As a result, the MnS0.5Se0.5/N-G hybrids delivered superior Li/Na storage capacities with outstanding rate performance as well as satisfactorily lasting stability (1039/457 mA h g–1 at 0.1 A g–1 for LIBs/SIBs). Additionally, full-cell LIBs of the anodic MnS0.5Se0.5/N-G constructed with cathodic LiFePO4 (LFP) further confirmed the promising future for their practical application.