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The compatibility and effectiveness of nanoparticles with the existing additives in formulated oil are still unclear. In the present study, some lubricant additives were selected to modify nanoparticles to obtain friendly capped nano-MoS₂. Various polyisobutyleneamine succinimide (PIBS) concentrations were applied to investigate the lubrication effectiveness of capped nano-MoS₂. The results showed that the reduction in COF and wear volume of friendly capped nanoparticles without PIBS reached about 35% and 75% in comparison with those of the base oil respectively. However, the average coefficient of friction and wear volume loss of nano oil increased with PIBS concentration in the range of 0.05%–1%. By scanning electron microscope, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy analysis, it is identified that (i) MoS₂ tribofilm was formed on the wear track for the oil with nano-MoS₂ and (ii) wear scar was smooth for nano-MoS₂ with low PIBS concentration and without PIBS, while it showed plowing wear when containing high PIBS concentration. Copyright © 2016 John Wiley & Sons, Ltd.

Electrochemical water splitting to generate molecular hydrogen requires catalysts that are cheap, active, and stable, particularly for alkaline electrolyzers, where the cathodic hydrogen evolution reaction is slower in base than in acid even on platinum. Herein, we describe the synthesis of new hollow Chevrel-phase NiMo₃S₄ and its alkaline hydrogen evolution reaction (HER) performance: onset potential of −59 mV, Tafel slope of 98 mV per decade, and exchange current density of 3.9×10⁻² mA cm⁻². This Chevrel-phase chalcogenide also demonstrates outstanding long-term stability under harsh HER cycling conditions. Chevrel-phase nanomaterials show promise as efficient, low-cost catalysts for alkaline electrolyzers.

Happy Holloween: A hollow chevrel-phase NiMo₃S₄ was prepared by a template-directed anion exchange strategy. This inexpensive, readily made material shows a good performance for generating H₂ fuel in alkaline electrolyte.

Through a facile and effective strategy by employing lithium molten salts the controlled synthesis of 2H- and 1T-MoS₂ monolayers with high-yield production is achieved. Both phases of MoS₂ monolayers exhibit high stabilities. When used as a catalyst for hydrogen evolution, these phased MoS₂ monolayers deliver respective advantages in the field of electro- and photo-catalytic hydrogen evolution.

It is critically important to characterize the band alignment in semiconductor heterojunctions (HJs) because it controls the electronic and optical properties. However, the well-known Anderson's model usually fails to predict the band alignment in bulk HJ systems due to the presence of charge transfer at the interfacial bonding. Atomically thin 2D transition metal dichalcogenide materials have attracted much attention recently since the ultrathin HJs and devices can be easily built and they are promising for future electronics. The vertical HJs based on 2D materials can be constructed via van der Waals stacking regardless of the lattice mismatch between two materials. Despite the defect-free characteristics of the junction interface, experimental evidence is still lacking on whether the simple Anderson rule can predict the band alignment of HJs. Here, the validity of Anderson's model is verified for the 2D heterojunction systems and the success of Anderson's model is attributed to the absence of dangling bonds (i.e., interface dipoles) at the van der Waal interface. The results from the work set a foundation allowing the use of powerful Anderson's rule to determine the band alignments of 2D HJs, which is beneficial to future electronic, photonic, and optoelectronic devices.

The band alignment of stacked 2D material heterojunctions is experimentally proven to follow the Anderson's model. Based on this discovery it is demonstrated that electron affinity and band gap values are sufficient to construct the band alignment of stacked 2D heterojunctions.

A bottom-up growth approach based on the assembly of binary atomic constituents delivers precise control over the edge termination and dimensions of nanostructures. Here, the dimensional crossover of MoS₂ from 1D nanoribbons to 2D islands synthesized by the assembly of Mo and S atoms on Au(100) surface is studied. Low-temperature scanning tunneling microscopy and in situ Q-plus non-contact atomic force microscopy are employed to elucidate the edge structure of MoS₂ nanoribbons at the atomic scale, where three types of zigzag Mo-edges with different sulfur terminations are observed. It is found that the thermodynamic instability of the armchair edges causes the 1D system to develop faceted zigzag edges which manifests in the morphological evolution from 1D ribbons to 2D triangles as the system size increases.

The dimensional crossover of MoS₂ from 1D nanoribbons to 2D islands synthesized by the assembly of Mo and S atoms on Au(100) surface is studied. It is found that the thermodynamic instability of the armchair edges causes the 1D system to develop faceted zigzag edges, which manifests in the morphological evolution from 1D ribbons to 2D triangles as the system size increases.

Dual emission quantum dots (QDs) have attracted considerable interest as a novel phosphor for constructing ratiometric optical thermometry because of its self-referencing capability. In this work, the exploration of codoped Zn–In–S QDs with dual emissions at ≈512 and ≈612 nm from intrinsic Cu and Mn dopants for ratiometric temperature sensing is reported. It is found that the dopant emissions can be tailored by adjusting the Mn-to-Cu concentration ratios, enabling the dual emissions in a tunable manner. The energy difference between the conduction band of the host and Cu dopant states is considered as the key for the occurrence of Mn ion emission. The as-constructed QD ratiometric temperature sensor exhibits a totally robust stability with a fluctuation of ≈I_Cu/I_tot versus times lower than 1% and almost no hysteresis in cycles over a broad window of 100–320 K. This discovery represents that the present cadmium-free, intrinsic dual-emitting codoped QDs can open a new door for the synthesis of novel QDs with stable dual emissions, which poise them well for challenging applications in optical nanothermometry.

A robust and stable ratiometric temperature sensor based on Zn–In–S QDs with intrinsic dual-dopant ion emissions is investigated. The fluctuation of ≈I_Cu/I_tot versus time is lower than 1% and the sensor shows almost no hysteresis in cycles over a broad operating temperature window from 100 to 320 K.

SnIP is the first atomic-scale double helical semiconductor featuring a 1.86 eV bandgap, high structural and mechanical flexibility, and reasonable thermal stability up to 600 K. It is accessible on a gram scale and consists of a racemic mixture of right- and left-handed double helices composed by [SnI] and [P] helices. SnIP nanorods <20 nm in diameter can be accessed mechanically and chemically within minutes.