The ambiguous mechanism of electrocatalysts for oxygen evolution reaction (OER) greatly hinders their industrial applications towards renewable and clean energy conversion. Here, we elaborately prepared cobalt sulfide catalyst to give...

Molybdenum disulfide (MoS 2 ) has attracted much attention as a promising alternative to Pt-based catalysts for highly efficient hydrogen generation. However, it suffers sluggish kinetics for driving the hydrogen evolution reaction (HER) process because of inert basal planes, especially in alkaline solution. Here, we show a combination of heteroatom doping and phase transformation strategies to engineer the inplane structure of MoS 2 , that trigger their catalytic activities. Systematic characterizations are performed with advanced aberration-corrected microscopy and X-ray techniques, indicating that an as-designed MoS 2 catalyst has a distorted zigzagchain superlattice in metallic phase, while its in-plane structure was engineered via the incorporation of cobalt and oxygen species. The optimal Co, O dual-doped metallic phase molybdenum disulfide (1T-MoS 2 ) electrocatalyst shows a significantly enhanced HER activity with a low overpotential of 113 mV at 10 mA cm −2 and corresponding small Tafel slope of 50 mV dec −1 , accompanied by the robust stability in alkaline media. The calculated turnover frequency is higher than 6.65 H 2 s −1 at an overpotential of 200 mV. More indepth insights from the first-principle calculations illustrate that the water dissociation as a rate-determining step was largely accelerated by the in-plane Co−O−Mo species and fast electron transfer of the catalyst. Benefiting from ingenious design and fine identifications, this work provides a fundamental understanding of the relationships among heteroatom doping, phase transformation, and performance for MoS 2 -based catalysts.

Despite recent advances in controlling ice formation and growth, it remains a challenge to design anti‐icing materials in various fields from atmospheric to biological cryopreservation. Herein, tungsten diselenide (WSe2)‐polyvinyl pyrrolidone (PVP) nanoparticles (NPs) are synthesized through one‐step solvothermal route. The WSe2‐PVP NPs show synergetic ice regulation ability both in the freezing and thawing processes. Molecularly speaking, PVP containing amides group can form hydrogen bonds with water molecules. At a macro level, the WSe2‐PVP NPs show adsorption‐inhibition and photothermal conversation effects to synergistically restrict ice growth. Meanwhile, WSe2‐PVP NPs are for the first time used for the cryopreservation of human umbilical vein endothelial cell (HUVEC)‐laden constructs based on rapid freezing with low concentrations of cryoprotectants (CPAs), the experimental results indicate that a minimal concentration (0.5 mg mL−1) of WSe2‐PVP NPs can increase the viabilities of HUVECs in the constructs post cryopreservation (from 55.8% to 83.4%) and the cryopreserved constructs can also keep good condition in vivo within 7 days. Therefore, this work provides a novel strategy to synergistically suppress the formation and growth of the ice crystalsfor the cryopreservation of cells, tissues, or organs.

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Despite the fact that two-dimensional layered magnetic materials hold immense potential applications in the field of spintronic devices, tunable magnetism is still a challenge due to the lack of controllable synthesis. Herein, high-quality single crystals MPS3 (M= Mn, Fe) of millimeter size were synthesized through the chemical vapor transport method. After systemic structural characterizations, magnetic properties were studied on the bulk MPS3 layers through experiments, along with first principle theoretical calculations. The susceptibilities as well as the EPR results evidently revealed unique isotropic and anisotropic behavior in MnPS3 and FePS3 crystals, respectively. It is worth noting that both of these materials show antiferromagnetic states at measured temperatures. The estimated antiferromagnetic transition temperature is 78 K for bulk MnPS3 and 123 K for FePS3 crystals. The spin polarized density functional theory calculations confirmed that the band gap of the antiferromagnetic states could be generated owing to asymmetric response all over the energy range. The ferromagnetic state in MnPS3 and FePS3 is less stable as compared to the antiferromagnetic state, resulting in antiferromagnetic behavior. Additionally, frequency-dependent dielectric functions for parallel and perpendicular electric field component vectors, along with the absorption properties of MPS3, are thoroughly investigated.

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