[Mo3S13]2– clusters have become known as one of the most efficient catalysts for the hydrogen evolution reaction (HER) because most of the sulfur (S) atoms in the cluster are exposed, resulting in many active sites. However, the origin of the cluster formation and active S sites in the cluster is unknown, hindering the development of efficient catalysts. Herein, the mechanism of the transition from amorphous MoS3 to [Mo3S13]2– clusters is systematically investigated. In addition, the active S sites have been identified by the selective removal of S atoms via low-temperature heat treatment. In summary, we believe that the clusters grow from amorphous MoS3 with apical S atoms, and bridging S atoms are the active HER sites in the [Mo3S13]2– clusters. The clusters deposited on carbon nanotubes exhibited good electrochemical HER activity with a low onset potential of −96 mV, a Tafel slope of 40 mV/decade, and stability for 1000 cycles.

An effective way of covalently functionalizing graphene with a chitosan polymer via a nitrene chemistry is demonstrated. The biofunctionalized graphene is prepared by the chemical reduction of graphene oxide using a nitrene chemistry, and then covalently grafting chitosan to the graphene surface. The effectiveness of the biofunctionalized graphene as a reinforcing filler (4 wt%) in a chitosan polymer matrix is verified by the dramatic enhancement of the mechanical properties (breaking stress = 330%, Young's modulus = 243%) and the electrical conductivity (0.3 S m−1) without much loss in the elongation‐at‐break. The reinforcing effect can be explained by both the homogeneous dispersion of graphene within the matrix and the strong bond arising from the intrinsically intimate contact between the graphene and the matrix. The high antimicrobial activity of the biofunctionalized graphene compared with graphene oxide and chemically reduced graphene may be because of the presence of chitosan polymer on the edges of the graphene. The strong, antimicrobial graphene‐filled composite film can be used for food packaging and for coating various biomedical devices, where bacterial surface colonization is undesirable.

Linear carbon chains (LCCs) consisting of sp-hybridized carbon atoms are considered a fascinating 1D system and could be used in the fabrication of the next-generation molecular devices because of its ideal linear atomic nature. A large portion of long LCCs inside multi-walled carbon nanotubes (MWCNTs) were synthesized by atmospheric arc discharge in the presence of boron. Closed-end growth of MWCNTs in the arc process is suggested as a critical condition for the simultaneous growth of LCCs within the inner cores of carbon nanotubes. The strong Raman line around 1850 cm-1 was used to characterize the degree of *Manuscript Click here to view linked References

Carbon nanotubes have shown great potential as conductive fillers in various composites, macro-assembled fibers, and transparent conductive films due to their superior electrical conductivity. Here, we present an effective defect engineering strategy for improving the intrinsic electrical conductivity of nanotube assemblies by thermally incorporating a large number of boron atoms into substitutional positions within the hexagonal framework of the tubes. It was confirmed that the defects introduced after vacuum ultraviolet and nitrogen plasma treatments facilitate the incorporation of a large number of boron atoms (ca. 0.496 atomic %) occupying the trigonal sites on the tube sidewalls during the boron doping process, thus eventually increasing the electrical conductivity of the carbon nanotube film. Our approach provides a potential solution for the industrial use of macro-structured nanotube assemblies, where properties, such as high electrical conductance, high transparency, and lightweight, are extremely important.

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