The discovery of two-dimensional electron gases at the heterointerface between two insulating perovskite-type oxides, such as LaAlO 3 and SrTiO 3 , provides opportunities for a new generation of all-oxide electronic devices. Key challenges remain for achieving interfacial electron mobilities much beyond the current value of approximately 1,000 cm 2 V -1 s -1 (at low temperatures). Here we create a new type of two-dimensional electron gas at the heterointerface between SrTiO 3 and a spinel g-Al 2 O 3 epitaxial film with compatible oxygen ions sublattices. Electron mobilities more than one order of magnitude higher than those of hitherto-investigated perovskite-type interfaces are obtained. The spinel/perovskite twodimensional electron gas, where the two-dimensional conduction character is revealed by quantum magnetoresistance oscillations, is found to result from interface-stabilized oxygen vacancies confined within a layer of 0.9 nm in proximity to the interface. Our findings pave the way for studies of mesoscopic physics with complex oxides and design of high-mobility all-oxide electronic devices.

To construct photocatalytically active MOFs, various strategies have recently been developed. We have synthesized and characterized a new metal-organic framework (MOF-253-Pt) material through immobilizing a platinum complex in 2,2 0 -bipyridine-based microporous MOF (MOF-253) using a post-synthesis modification strategy.The functionalized MOF-253-Pt serves both as a photosensitizer and a photocatalyst for hydrogen evolution under visible-light irradiation. The photocatalytic activity of MOF-253-Pt is approximately five times higher than that of the corresponding complex. The presence of the short Pt/Pt interactions in the framework was revealed with extended X-ray absorption fine structure (EXAFS) spectroscopy and low temperature luminescence. These interactions play an important role in improving the photocatalytic activity of the resulting MOF.

Methods for the hydrogenation of CO into valuable chemicals are in great demand but their development is still challenging. Herein, we report the selective hydrogenation of CO into ethanol over non-noble cobalt catalysts (CoAlO ), presenting a significant advance for the conversion of CO into ethanol as the major product. By adjusting the composition of the catalysts through the use of different prereduction temperatures, the efficiency of CO to ethanol hydrogenation was optimized; the catalyst reduced at 600 ° gave an ethanol selectivity of 92.1 % at 140 °C with an ethanol time yield of 0.444 mmol g h . Operando FT-IR spectroscopy revealed that the high ethanol selectivity over the CoAlO catalyst might be due to the formation of acetate from formate by insertion of *CH , a key intermediate in the production of ethanol by CO hydrogenation.

Although porous materials based on coordination compounds, including metal-organic frameworks (MOFs) and porous coordination polymers (PCPs), have well-defined pore structures and promising properties, they can efficiently be prepared by conventional and facile methods. Among coordination compounds, Prussian blue (PB) and its analogues (PBA) show high physical/chemical properties and potential as a multifunctional platform for various applications such as information records, sensing, batteries, biomedicine, imaging, and water purification. This review introduces versatile paths for nano- and meso-structural controls and demonstrates strong relationship between nanoarchitectures and properties with regard to PB and PBAs. This review will provide some guidance for future derivations of nanoarchitectonics based on coordination compounds which are PB and PBA.

Solvothermally synthesized Ga2O3 nanoparticles are incorporated into liquid metal/metal oxide (LM/MO) frameworks in order to form enhanced photocatalytic systems. The LM/MO frameworks, both with and without incorporated Ga2O3 nanoparticles, show photocatalytic activity due to a plasmonic effect where performance is related to the loading of Ga2O3 nanoparticles. Optimum photocatalytic efficiency is obtained with 1 wt % incorporation of Ga2O3 nanoparticles. This can be attributed to the sub-bandgap states of LM/MO frameworks, contributing to pseudo-ohmic contacts which reduce the free carrier injection barrier to Ga2O3.