Hydrogen spillover onto the WO 3 (001) surface and further into the bulk in the presence of a platinum catalyst was investigated by density functional theory calculations. The diffusion pathways are designed based on the energetic preference of hydrogen adsorption. Atomic H migrates from a platinum catalyst, where it is adsorbed upon H 2 dissociative chemisorption, to terminal oxygen on WO 3 (001) surface, followed by migration to in-plane oxygen and then diffusion across the surface or insertion in the lattice. We first theoretically corroborated the role of water in facilitating the hydrogen spillover process. The otherwise prohibitively high activation barriers were considerably reduced with the participation of water, which agrees well with experimental facts. The high mobility of H inside the WO 3 lattice was also identified with low calculated diffusion barriers for several selected migration pathways. Finally, the effects of hydrogen concentration and electronic structures of H x WO 3 were investigated. This study unravels the formation mechanisms of H x WO 3 via spillover and sheds light on the microscopic surface and bulk processes.
Developing rewritable papers has gathered immense interest in recent times in view of developing sustainability in print media without exhausting environmental resources. We herein present a rapid and facile procedure for the fabrication of a communication medium by treating the surface of a paper with synthetic organic molecules, after which plain water could be used as an ink to print and reprint numerous times on the treated paper before disposal. Interestingly, as the paper comes in contact with water, the molecules are driven to reorganize in a slip-stacked arrangement. This alters their ground and excited state properties by hydrogen-bond-assisted nonradiative decay, in which the associated changes are visible to the naked eye. The changes evolved are sensitive to the solubility parameter of the solvent and thermally reversible, thus linking the hydrochromic property to the paper. Against a background of concerns over a rise in counterfeiting and leaks of confidential information, prospects for encrypted communications and anticounterfeiting is herein demonstrated.
Electrical and optical properties of transparent conducting oxides (TCOs) are of essential importance for optoelectronics. Electronic structures are keys to the understanding of these properties. The geometrical and electronic structures of body-centered cubic In 2 O 3 n-typedoped by Group 14 and fifth-period main group elements (Sb, Te and I) are systematically investigated. The calculated electronic structures reveal a good hybridization between the O-2p states and the s-states of Si, Ge and Sn, resulting in superior electronic properties, such as a freeelectron-like band feature, a large band width (> 2 eV), a low effective mass (m*=0.2m 0 ) and a high electron group velocity (≥8.35×10 5 m/s). The charge localization on the dopants leads to inferior electronic properties of In 2 O 3 doped by other dopants. The calculated defect formation energy indicates that the formation of both neutral and +1 charge state Sn is spontaneous in indium oxide.
Heterogeneously catalyzed deoxydehydration (DODH) ordinarily occurs over oxide supported ReOx sites. A comparably high activity of MoOx/TiO2(101) suggests that it is a promising low-cost DODH catalyst that can replace Re-based catalysts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.