The electronic states of partially hydrogenated graphene (HG) structures are studied by the density functional theory calculations. Several types of HG configurations, including randomly removing of H pair, randomly removing individual H atoms, and ordered H pairs removal, are investigated. We find that the configurations with randomly removing H pairs are most energetically favorable. More interestingly, the band gap for such configurations decrease with H concentration and approaches zero around 67% H coverage. The ability to continuously tune the band gap of hydrogenated graphene from 0 to 4.66 eV by different H coverage provides a new pathway for engineering the electronic structure of graphene materials and enhances their applications in electronics and photonics.

The chemisorption of specific optically active compounds on metal surfaces can create catalytically active chirality transfer sites. However, the mechanism through which these sites bias the stereoselectivity of reactions (typically hydrogenations) is generally assumed to be so complex that continued progress in the area is uncertain. We show that the investigation of heterogeneous asymmetric induction with single-site resolution sufficient to distinguish stereochemical conformations at the submolecular level is finally accessible. A combination of scanning tunneling microscopy and density functional theory calculations reveals the stereodirecting forces governing preorganization into precise chiral modifier-substrate bimolecular surface complexes. The study shows that the chiral modifier induces prochiral switching on the surface and that different prochiral ratios prevail at different submolecular binding sites on the modifier at the reaction temperature.

An anti-freezing and moisturizing conductive hydrogel, capable of harvesting energy from moisture, was developed by incorporating tannic acid and carbon nanotubes into polyvinyl alcohol containing a water–glycerol dispersion.

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Carbon nanotubes (CNTs) have been shown to modify some properties of nanomaterials and to modify chemical reactions confined inside their channels, which are formed by curved graphene layers. Here we studied ammonia synthesis over Ru as a probe reaction to understand the effect of the electron structure of CNTs on the confined metal particles and their catalytic activity. The catalyst with Ru nanoparticles dispersed almost exclusively on the exterior nanotube surface exhibits a higher activity than the CNT-confined Ru, although both have a similar metal particle size. Characterization with TEM, N(2) physisorption, H(2) chemisorption, temperature-programmed reduction, CO adsorption microcalorimetry, and first-principles calculations suggests that the outside Ru exhibits a higher electron density than the inside Ru. As a result, the dissociative adsorption of N(2), which is an electrophilic process and the rate-determining step of ammonia synthesis, is more facile over the outside Ru than that over the inside one.