Island-in-Sea Structured Pt3Fe Nanoparticles-in-Fe Single Atoms Loaded in Carbon Materials as Superior Electrocatalysts toward Alkaline HER and Acidic ORR.

In this work, Pt3Fe nanoparticles (Pt3Fe NPs) with the ordered internal structure and Pt-rich shells surrounded by plenty of Fe single atoms (Fe SAs) as active species (Pt3Fe NP-in-Fe SA) loaded in the carbon materials are successfully fabricated, which are abbreviated as island-in-sea structured (IISS) Pt3Fe NP-in-Fe SA catalysts. Moreover, the synergistic effect of O-bridging between Pt3Fe NPs and Fe SAs, and the ordered internal structured Pt3Fe NPs with Pt-rich shells of an optimal thickness contributes to the achievement of the local acidic environments on the surfaces of Pt3Fe NPs in the alkaline hydrogen evolution reaction (HER) and the enhancement of the desorption rate of *OH intermediate in the acidic oxygen reduction reaction (ORR). In addition, the electronic interactions between Pt3Fe NPs and dispersed Fe SAs cannot only provide efficient electrons transfer, but also prevent the aggregation and dissolution of Pt3Fe NPs. Furthermore, the overpotential and the half wave potential of the as-prepared IISS Pt3Fe NP-in-Fe SA catalysts toward the alkaline HER and toward the acidic ORR are 8 mV at a current density of 10 mA cm-2 and 0.933 V, respectively, which is 29 lower and 86 mV higher than those (37 mV and 0.847 V) of commercial Pt/C catalysts.

The molecular mechanisms of cuproptosis and its relevance to cardiovascular disease.

Recently, cuproptosis has been demonstrated to be a new non-apototic cell death mode that is characterized by copper dependence and the regulation of mitochondrial respiration. Cuproptosis is distinct from known cell death modes such as apoptosis, necrosis, pyroptosis, or ferroptosis. Excessive copper induces cuproptosis by promoting protein toxic stress reactions via copper-dependent anomalous oligomerization of lipoylation proteins in the tricarboxylic acid (TCA) cycle and reducing iron-sulfur cluster protein levels. Ferredoxin1 (FDX1) promotes dihydrolipoyl transacetylase (DLAT) lipoacylation and abates iron-sulfur cluster proteins by reducing Cu2+ to Cu+, inducing cell death. Copper homeostasis depends on the copper transporter, and disturbances to this homeostasis cause cuproptosis. Recent evidence has shown that cuproptosis plays a significant role in the occurrence and development of many cardiovascular diseases, such as myocardial ischemia/reperfusion (I/R) injury, heart failure, atherosclerosis, and arrhythmias. Copper chelators, such as ammonium tetrathiomolybdate(VI) and DL-Penicillamine, may ease the above cardiovascular diseases by inhibiting the cuproptosis pathway. Oxidative phosphorylation inhibitors may inhibit cuproptosis by inhibiting protein stress response. In conclusion, cuproptosis plays an essential role in cardiovascular disease pathogenesis. Inhibition of cardiovascular cuproptosis is expected to become a potential treatment. Here, we will thoroughly review the molecular mechanisms involved in cuproptosis and its significance in cardiovascular disease.

High-Performance Electrocatalytic Conversion of N2 to NH3 Using 1T-MoS2 Anchored on Ti3C2 MXene under Ambient Conditions.

Herein, 1T-MoS2 nanospots assembled on conductive Ti3C2 MXene (1T-MoS2@Ti3C2) are first developed to regard as efficient electrocatalytic nitrogen fixation catalysts with high selectivity. The 1T-MoS2@Ti3C2 composite exhibits outstanding NRR activity with a faradic efficiency (FE) of 10.94% and a NH3 yield rate of 30.33 µg h-1 mg-1cat. at -0.3 V versus RHE. Notably, the 1T-MoS2@Ti3C2 composite displays excellent stability and durability during the recycling test. The outstanding NRR catalytic activity is primarily attributed to the synergy effect between 1T-MoS2 and Ti3C2 MXene. In addition, the isotopic experiment confirms the synthesized NH3 deriving from the conversion of the supplied nitrogen.

Sulfur Vacancy-Rich O-Doped 1T-MoS2 Nanosheets for Exceptional Photocatalytic Nitrogen Fixation over CdS.

Here, we reported that sulfur vacancy-rich O-doped 1T-MoS2 nanosheets (denoted as SV-1T-MoS2) can surpass the activity of Pt as cocatalysts to assist in the photocatalytic nitrogen fixation of CdS nanorods. SV-1T-MoS2 cocatalysts exhibit sulfur vacancies, O-doping, more metallic 1T phase, and high electronic conductivity, thus leading to the exposure of more active edge sites, high Brunauer-Emmett-Teller surface area, enhanced visible light absorption, and improved electron separation and transfer, which are beneficial for photocatalytic nitrogen fixation. Consequently, the optimized 30 wt % SV-1T-MoS2-/CdS composites exhibit an outstanding nitrogen fixation rate of 8220.83 µmol L-1 h-1 g-1 and long-term stability under simulated solar light irradiation, significantly higher than pure CdS nanorods, CdS-Pt (0.1 wt %), and 30 wt % 1T-MoS2/CdS composites. The catalytic mechanism of photocatalytic nitrogen fixation on SV-1T-MoS2 is discussed by density functional theory calculations.

Metallic 1T-phase MoS2 quantum dots/g-C3N4 heterojunctions for enhanced photocatalytic hydrogen evolution.

Recently, molybdenum disulfide (MoS2) has been regarded as an efficient non-precious-metal co-catalyst for photocatalytic hydrogen (H2) evolution, however, its inherent low-density active site and poor electron transfer efficiency have essentially limited its photocatalytic properties. Here we report that 1T-MoS2 quantum dots (QDs) can act as co-catalysts in assisting the photocatalytic H2 evolution to form heterostructures with g-C3N4 nanosheets (denoted as 1T-MoS2 QDs@g-C3N4). Benefiting from the abundance of exposed catalytic edge sites and the excellent intrinsic conductivity of 1T-MoS2 QDs, an optimized 1T-MoS2 QD@g-C3N4 composite (15 wt%) exhibits an extraordinary photocatalytic H2 evolution rate of 1857 µmol h-1 g-1 under simulated solar light irradiation, apparently 37.9 times higher than that of pure g-C3N4 NSs (49 µmol h-1 g-1). Meanwhile, the 1T-MoS2 QD@g-C3N4 composites exhibit a good stability in the cyclic runs for the photocatalytic H2 production. The high efficient photocatalytic activity and stability of the 1T-MoS2 QD@g-C3N4 composite is primarily attributed to the following reasons: (1) the introduction of 1T-MoS2 QDs results in a stronger light absorption capability in comparison with pure g-C3N4; (2) the tiny particle size of 1T-MoS2 QDs, in which edges and basal surface are catalytically active, provides a proliferated density of catalytically active sites; (3) 1T-MoS2 QD co-catalysts with metallic characteristics could act as efficient electron acceptors, which builds up a highly efficient pathway for photo-generated electrons from the CB of g-C3N4 NSs to 1T-MoS2 and thus realizes rapid spatial charge separation. The improved light harvesting ability, increased catalytically active sites, as well as increased separation of charge carriers could be responsible for the improved photocatalytic H2 evolution. This work will provide new insight for the design and fabrication of smarter, cheaper and more robust artificial photocatalysts for photocatalytic H2 evolution.

Fabrication of molybdenum and tungsten oxide, sulfide, phosphide (MoxW1-xO2/MoxW1-xS2/MoxW1-xP) porous hollow nano-octahedrons from metal-organic frameworks templates as efficient hydrogen evolution reaction electrocatalysts.

A metal-organic frameworks-derived sulfuration and phosphorization method is developed for constructing a hydrogen evolution reaction (HER) electrocatalyst (MoWOSP@C), which is composed of MoxW1-xO2 nanoparticles, MoxW1-xS2 nanosheets, and MoxW1-xP nanoparticles coated with a porous hollow carbon matrix. The three-dimensional MoWOSP@C nano-octahedron shows excellent catalytic activity with a low overpotential of -118 mV at a current density of -10 mA cm-2 and a small Tafel slope of 74.1 mV dec-1, which are all higher than those of the single phase components. The outstanding performance of the MoWOSP@C is due to the highly exposed active sites and synergistic effects of the MoxW1-xS2 and MoxW1-xP, carbon conductive matrix and mesoporous hollow structures.