Two-dimensional materials are attractive for use in next-generation nanoelectronic devices because, compared to one-dimensional materials, it is relatively easy to fabricate complex structures from them. The most widely studied two-dimensional material is graphene, both because of its rich physics and its high mobility. However, pristine graphene does not have a bandgap, a property that is essential for many applications, including transistors. Engineering a graphene bandgap increases fabrication complexity and either reduces mobilities to the level of strained silicon films or requires high voltages. Although single layers of MoS(2) have a large intrinsic bandgap of 1.8 eV (ref. 16), previously reported mobilities in the 0.5-3 cm(2) V(-1) s(-1) range are too low for practical devices. Here, we use a halfnium oxide gate dielectric to demonstrate a room-temperature single-layer MoS(2) mobility of at least 200 cm(2) V(-1) s(-1), similar to that of graphene nanoribbons, and demonstrate transistors with room-temperature current on/off ratios of 1 × 10(8) and ultralow standby power dissipation. Because monolayer MoS(2) has a direct bandgap, it can be used to construct interband tunnel FETs, which offer lower power consumption than classical transistors. Monolayer MoS(2) could also complement graphene in applications that require thin transparent semiconductors, such as optoelectronics and energy harvesting.

合成一种三环喹唑啉的共轭微孔聚合物(TQ-CMPs)并用水热法使二硫化钼原位生长在其骨架表面，制备出一种新型复合电催化析氢催化剂并研究了它的电催化析氢活性。结果表明，TQ-CMPs与MoS₂的质量比为2∶1的催化剂具有优异的电催化析氢活性，其过电势为71 mV，Tafel斜率为52 mV·dec^-1。比表面积较大的TQ-CMPs，使MoS₂的分散度提高、避免了MoS₂的堆积和聚集并使更多的MoS₂边缘暴露，从而提高了催化剂的效率。TQ-CMPs丰富的孔道结构和延伸的π共轭骨架，有利于质量运输和电荷转移。

用磁控溅射在硅片上制备MoS₂和Ti-MoS₂薄膜，并将其在恒温恒湿箱中在AT 30℃、RH 70%条件下存储360 h。使用XRD谱、XPS谱和紫外-可见分光光度计、四探针测试仪表征分析薄膜的结构、在恒温恒湿条件下存储前后的表面化学状态和电学性能，研究了Ti掺杂对薄膜抗氧化性和电学性能的影响。结果表明：Ti掺杂影响MoS₂薄膜的晶体取向。随着Ti靶电流的增大薄膜的结晶性变差，Ti靶电流为0.6A时薄膜呈无定型结构且禁带宽度减小、电导率提高；在恒温恒湿条件下存储后薄膜的部分氧化而呈MoS₂与MoO₃的复合状态，随着Ti靶电流的增大I_Mo-O/I_Mo-S比提高、禁带宽度略有增大，Ti靶电流为0.4A的Ti-MoS₂薄膜其化学稳定性较高。

Substitutional doping of transition metal dichalcogenides (TMDs) may provide routes to achieving tunable p-n junctions, bandgaps, chemical sensitivity, and magnetism in these materials. In this study, we demonstrate in situ doping of monolayer molybdenum disulfide (MoS2) with manganese (Mn) via vapor phase deposition techniques. Successful incorporation of Mn in MoS2 leads to modifications of the band structure as evidenced by photoluminescence and X-ray photoelectron spectroscopy, but this is heavily dependent on the choice of substrate. We show that inert substrates (i.e., graphene) permit the incorporation of several percent Mn in MoS2, while substrates with reactive surface terminations (i.e., SiO2 and sapphire) preclude Mn incorporation and merely lead to defective MoS2. The results presented here demonstrate that tailoring the substrate surface could be the most significant factor in substitutional doping of TMDs with non-TMD elements.

Due to its electronic-grade quality and potential for scalability, two-dimensional (2D) MoS2 synthesized by chemical vapor deposition (CVD) has been widely explored for electronic/optoelectronic applications. As 2D MoS2 can be considered a 100% surface, its unique intrinsic properties are inevitably altered by the substrate upon which it is grown. However, systematic studies of substrate-layer interactions in CVD-grown MoS2 are lacking. In this study, we have analyzed built-in strain and charge doping using Raman and photoluminescence spectroscopy in 2D MoS2 grown by CVD on four unique substrates: SiO2/Si, sapphire, Muscovite mica, and hexagonal boron nitride. We observed decreasing strain and charge doping in grown MoS2 as the substrates become less rough and more chemically inert. The possible origin of strain was investigated through atomic force microscopy roughness measurements of the as-grown layer and substrate. Our results provide direction for device optimization through careful selection of the growth substrate and pave the way for further investigations to unravel the complex nature of the 2D monolayer-substrate interface.

A biosensor for hydrogen peroxide (HO) has been developed based on the use of MoS nanosheets and graphite that are assembled to form a microfiber hybrid structure. The MoS nanosheets are synthesized in situ on a graphite microfiber. The chemical composition and surface morphology of the microfiber hybrid structure has been characterized. The microfiber is shown to display peroxidase-mimicking activity. In the next step, horseradish peroxidase, methylene blue, and chitosan are co-immobilized on the microfiber electrode. The use of MoS nanosheets warrants high electrochemical activity of immobilized enzyme on the electrode surface. The modified microfiber electrode, best operated at a voltage of - 0.3 V (vs. Ag/AgCl), can be used to sense HO with a linear response in the 0.1 to 90 μM concentration range and with a determination limit of 30 nM (at S/N = 3). The good response is attributed to the synergistic enhancement of the synthetic nanozymes (few-layered MoS nanosheets) and immobilized natural horseradish peroxidase (HRP). Grapical abstract.

Herein, ZnS quantum dots on MnS2 (ZnS/MnS2) nanoparticles. Was prepared via the facile and simple method. The ZnS/MnS2 nanocomposites were characterized into attained optical, morphological, structural, and surface attributes using different analytical routs. The average crystallite size of MnS2 and ZnS/MnS2 nanocomposites are 27.2 and 14.8nm via calculated from Scherrer's equation. Subsequent, the photo-catalytic and -electrochemical attributes of synthesized ZnS/MnS2 nanocomposites were as well as presented. The ZnS/MnS2 nanocomposites electrode represented a potential influence on the decomposition of acetaminophen, which was higher than that of MnS2 nanoparticles electrode. The high amount of ZnS QDs in MnS2 samples has a high decomposition efficiency of acetaminophen due to the conduction band position and valence band position of ZnS QDs are higher than that of MnS2. Influencing major factors on the decomposition of acetaminophen were evaluated and the removal of acetaminophen was performed at pH:3, 60mA cm(-2), and 0.1M NaCl concentration. The prepared electrode represented great stability and indicated the highest possible for treatment technology of wastewater. Comparison of the performances of the photo-assisted electrochemical (PAEC) electrochemical (EC) and photo-catalytic indicated that the hybrid process (PAEC) has high efficiency for acetaminophen degradation.