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Sodium tantalate, NaTaO 3 , is one of the best semiconductors for photocatalytic water splitting and CO 2 reduction. Doping with metal cations is crucial for enhancing the quantum efficiency of the desired reactions. Nevertheless, details related to the doping of the host metal oxide and activation by guest metal cations are not sufficiently known. The most fundamental question concerns the increase in the quantum efficiency via doping with guest cations that are impurities in the host lattice. In this study, the local environment of Sr cations, which are the typically used guest cations in NaTaO 3 , was characterized by extended X-ray absorption fine structure spectroscopy. The results reveal the presence of two Sr−O shells in the Srdoped NaTaO 3 photocatalysts. The small shell with an unexpectedly short Sr− O bond length of 1.96 Å corresponds to SrO 6 octahedra embedded in the corner-shared network of TaO 6 octahedra. The other shell with a Sr−O bond length of 2.60 Å corresponds to SrO 12 cuboctahedra with Sr cations at positions previously occupied by Na cations. Rietveld analysis of the X-ray diffraction data confirmed the formation of a NaTaO 3 −Sr(Sr 1/3 Ta 2/3 )O 3 solid solution to accommodate the two Sr−O shells in NaTaO 3 with no requirement for creating oxygen anion vacancies. Mechanisms for increasing the quantum efficiency via doping with Sr cations are discussed in the context of the revealed environment.

These findings suggest that the continuing use of RPDs is related to factors such as the patient's age, location of edentulous area, number of occluding pairs of teeth, and number of occlusal rests, satisfaction including pain while using RPDs, color of the artificial teeth, and tooth shape and set-up.

The first synthesis of planar-chiral benzosiloloferrocenes was achieved by the intramolecular reaction of 2-(dimethylhydrosilyl)arylferrocenes. The enantioselective cross dehydrogenative coupling of an sp(2) C-H bond of ferrocene with a Si-H bond proceeded efficiently with the use of a Rh-chiral diene catalyst.