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The structural, electrical, and optical properties of monolayer ruthenium oxide (RuO 2 ) nanosheets (NSs) fabricated by chemical exfoliation of a layered three-dimensional form of K-intercalated RuO 2 are studied systematically via experimental and computational methods. Monolayer RuO 2 NS is identified as having a distorted h-MX 2 structure. This is the first observation of a RuO 2 NS structure that is unlike the t-MX 2 structure of the RuO 2 layers in the parent material and does not have hexagonal symmetry. The distorted h-MX 2 RuO 2 NSs are shown to have optical transparency superior to that of graphene, thereby predicting the feasibility of applying RuO 2 NSs to flexible transparent electrodes. In addition, it is demonstrated that the semiconducting band structures of RuO 2 NSs can be manipulated to be semimetallic by adjusting the crystal structure, which is related to band-gap engineering. This finding indicates that RuO 2 NSs can be used in a variety of applications, such as flexible transparent electrodes, atomic-layer devices, and optoelectronic devices.

This study examines the development of lower temperature solid oxide fuel cells (SOFCs) and the incremental improvement in performance obtained from a wide range of techniques, from pressed anodes to tape-cast anodes, from gadolinia-doped ceria (GDC) single-layer electrolytes to erbium-stabilized bismuth oxide (ESB)/GDC bilayer, and from La0.6Sr0.4Co0.2Fe0.8normalO3−δ -GDC composite cathodes to optimized Bi2Ru2normalO7 -ESB composites. GDC single-layer electrolyte-based SOFCs were prepared from four different fabrications and exhibit maximum power densities ranging from 0.338 to 1.03W/cm2 at 650°C . At each fabrication stage, an ESB layer was applied to form a bilayer electrolyte. ESB was deposited by a range of techniques including colloidal deposition and pulsed laser deposition. The result confirms that depending on a fabrication route, the bilayer electrolyte can reduce the total area specific resistance (ASR) 33–49% and increase the maximum power density 44–93%. By using a combination of the materials and fabrication routes, a maximum power density of 1.95W/cm2 and 0.079Ωcm2 total cell ASR was achieved at 650°C for a bilayer cell.