Key Engineering Materials Vol. 388

Abstract: TiO2 powder was synthesized hydrothermally from titanium alkoxide ethanol solution in supercritical state and obtained anatase type crystalline powder sized ca. 20 nm. Dye-sensitized solar cells were fabricated with the powders and evaluated the power generation efficiencies.

Abstract: Photocatalytic proton reduction and water oxidation have been studied in a tris(2,2’-bipyridyl)ruthenium complex-catalyst system. Pyrochlore-type oxides have been used as proton reduction catalysts with a sacrificial electron donor (Na2EDTA) at pH 7 and as water oxidation catalysts with a sacrificial electron acceptor (K2S2O8) at pH 3. Rate constants for the proton reduction were estimated on the basis of photochemical processes. Yb2Ru2O7-δ was found to be the most active catalyst for proton reduction and water oxidation catalyst in this system.

Abstract: We successfully synthesized the novel mechanoluminescent material ZnS:Mn,Te with a wurtzite structure by controlling the pH of the solution used in the wet process. This material showed a distinct red mechanoluminescence (ML) with an increased intensity, being one order of magnitude higher than that of the sample prepared using a solid-state reaction. This marked increase in ML intensity was realized by eliminating ZnO and MnO impurities.

Abstract: We have discovered that Sr2MgSi2O7:Eu, SrCaMgSi2O7:Eu and Ca2MgSi2O7:Eu phosphors emit blue, blue-greenish and green light under the application of a mechanical stress respectively, called as mechanoluminescence (ML). The ML showed a similar spectrum as photoluminescence (PL), which indicated that ML is emitted from the same center of Eu2+ ions as PL. Such bright lights of ML emission can be observed by the naked eye when pressing these samples.