Highly Conductive Porous Transition Metal Dichalcogenides via Water Steam Etching for High-Performance Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries show significant advantages for next-generation energy storage systems owing to their high energy density and cost effectiveness. The main challenge in the development of long-life and high-performance Li–S batteries is to simultaneously facilitate the redox kinetics of sulfur species and suppress the shuttle effect of polysulfides. In this contribution, we present a general and green water-steam-etched approach for the fabrication of H- and O-incorporated porous TiS₂ (HOPT). The conductivity, porosity, chemisorptive capability, and electrocatalytic activity of HOPT are enhanced significantly when compared with those of raw TiS₂. The synthetic method can be expanded to the fabrication of other highly conductive transition metal dichalcogenides such as porous NbS₂ and CoS₂. The as-obtained HOPT can serve as both a substitute of conductive agents and an additive of interlayer materials. The optimal electrode delivers discharge capacities of 950 mA h g^–1 after 300 cycles at 0.5 C and 374 mA h g^–1 after 1000 cycles at 10 C. Impressively, an unprecedented reversible capacity of 172 mA h g^–1 is achieved after 2500 cycles at 30 C, and the average capacity fading rate per cycle is as low as 0.015%. Importantly, four half-cells based on this electrode in series could drive 60 light-emitting diode indicator modules (the nominal power 3 W) after 20 s of charging. The instantaneous current and power of this device on reaching 275 A g^–1 and 2611 W g^–1, respectively, indicate outstanding high-power discharge performance and potential applications in electric vehicles and other large-scale energy storage systems

Sandwich-Type NbS₂@S@I-Doped Graphene for High-Sulfur-Loaded, Ultrahigh-Rate, and Long-Life Lithium–Sulfur Batteries

Lithium–sulfur batteries practically suffer from short cycling life, low sulfur utilization, and safety concerns, particularly at ultrahigh rates and high sulfur loading. To address these problems, we have designed and synthesized a ternary NbS₂@S@IG composite consisting of sandwich-type NbS₂@S enveloped by iodine-doped graphene (IG). The sandwich-type structure provides an interconnected conductive network and plane-to-point intimate contact between layered NbS₂ (or IG) and sulfur particles, enabling sulfur species to be efficiently entrapped and utilized at ultrahigh rates, while the structural integrity is well maintained. NbS₂@S@IG exhibits prominent high-power charge/discharge performances. Reversible capacities of 195, 107, and 74 mA h g^–1 (1.05 mg cm^–2) have been achieved after 2000 cycles at ultrahigh rates of 20, 30, and 40 C, respectively, and the corresponding average decay rates per cycle are 0.022%, 0.031% and 0.033%, respectively. When the area sulfur loading is increased to 3.25 mg cm^–2, the electrode still maintains a high discharge capacity of 405 mAh g^–1 after 600 cycles at 1 C. Three half-cells in series assembled with NbS₂@S@IG can drive 60 indicators of LED modules after only 18 s of charging. The instantaneous current and power of the device reach 196.9 A g^–1 and 1369.7 W g^–1, respectively

Nanohybrid of Carbon Quantum Dots/Molybdenum Phosphide Nanoparticle for Efficient Electrochemical Hydrogen Evolution in Alkaline Medium

The exploration of highly efficient non-noble metal electrocatalysts for hydrogen evolution reaction (HER) under alkaline conditions is highly imperative but still remains a great challenge. In this work, the nanohybrid of carbon quantum dots and molybdenum phosphide nanoparticle (CQDs/MoP) has been firstly demonstrated as an efficient alkaline HER electrocatalyst. The CQDs/MoP nanohybrid is readily prepared through a charge-directed self-assembly of CQDs with phosphomolybdic acid (H₃PMo₁₂O₄₀) at the molecular level, followed by facile phosphatizing at 700 °C. The introduction of CQDs greatly helps to alleviate the agglomeration and surface oxidation of MoP nanoparticles and ensures each MoP nanoparticle to be electronically addressed, thus significantly enhancing the intrinsic catalytic activity of MoP. The optimized CQDs/MoP exhibits high-efficiency synergistic catalysis toward HER in 1 M KOH electrolyte with a low onset potential of −0.08 V and a small Tafel slope of 56 mV dec^–1 as well as high durability with negligible current loss for at least 24 h

Supplementary document for Three-dimensional location system based on an L-shaped array of Rydberg atomic receivers - 6438391.pdf

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Additional file 1 of The effects of oxaliplatin-based adjuvant chemotherapy in high-risk stage II colon cancer with mismatch repair-deficient: a retrospective study

Additional file 1: Fig S1. Flow of study