The crystal structure of a high-pressure phase of silane ͑SiH 4 ͒, observed between 10 and 25 GPa, is solved using powder synchrotron x-ray diffraction and shown to be of the SnBr 4 type. The phase is an insulating molecular solid with a monoclinic unit cell containing four tetrahedrally bonded molecules, space group P2 1 / c. Ab initio calculations show the SnBr 4 -type structure to be favored in this pressure range relative to other recently proposed structures. The fit of the pressure dependence of volume to the Birch-Murnagham equation of state gives the following parameters at ambient pressure if K 0 Ј is fixed to 4: V 0 = 250͑9͒ Å 3 and K 0 = 7.8͑9͒ GPa for the experimental data, and V 0 = 255͑2͒ Å 3 and K 0 = 6.1͑2͒ GPa for the data obtained from ab initio calculations.

The adsorption of molecules usually increases capacity and/or strength with the doping of surfaces with transition metals; furthermore, carbon nanostructures, i.e., graphene, carbon nanotubes, fullerenes, graphdiyne, etc., have a large specific area for gas adsorption. This review focuses on the reports (experimental or theoretical) of systems using these structures decorated with transition metals for mainly pollutant molecules’ adsorption. Furthermore, we aim to present the expanding application of nanomaterials on environmental problems, mainly over the last 10 years. We found a wide range of pollutant molecules investigated for adsorption in carbon nanostructures, including greenhouse gases, anticancer drugs, and chemical warfare agents, among many more.

Using density functional theory (DFT) and molecular dynamics (MD), we studied the interaction of a titanium atom with a half of a C60 fullerene (i.e., C30), formed from the corannulene structure with a pentagonal base. We considered atmospheric pressure and 300 K. We found that the most stable adsorption of the titanium atom on C30 occurs in the concave surface of the molecule. Afterward, we investigated the interaction of the system C30-titanium with carbon monoxide and carbon dioxide molecules, respectively. We found that each of these molecules is chemisorbed, with no dissociation. The value of the adsorption energy for the carbon monoxide molecule varies from -0.897 to -1.673 eV, and for the carbon dioxide molecule, it is between -1.065 and -1.274 eV. These values depend on the initial orientation of these molecules with respect to TiC30. Graphical Abstract The TiC30 system chemisorbs CO or CO2ᅟwith no dissociation at atmospheric pressure and 300K.

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We used first-principles molecular dynamics at atmospheric pressure and 300 K to simulate a graphene layer, a titanium slab, the high coverage of the graphene layer with titanium, and the masking of the titanium surface with a carbon layer. The calculations were performed using the Quantum Espresso code with the GGA approximation. We then calculated the energy band structure and the optical absorption and reflectivity of the decorated surfaces. We found significant changes in these properties.

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