Highly efficient water oxidation utilizing visible photons of up to 600 nm is a crucial step in artificial photosynthesis. Here we present a highly active photocatalyst for visible-light-driven water oxidation, consisting of single-crystalline meso- and macroporous LaTiO(2)N (LTON) with a band gap of 2.1 eV, and earth-abundasnt cobalt oxide (CoO(x)) as a cocatalyst. The optimized CoO(x)/LTON had a high quantum efficiency of 27.1 ± 2.6% at 440 nm, which substantially exceeds the values reported for previous particulate photocatalysts with a 600-nm absorption edge.

As the 600 nm-class photocatalyst, BaTaO 2 N is one of the promising candidates of the perovskite-type oxynitride family for photocatalytic water splitting under visible light. The oxynitrides are routinely synthesized by nitriding corresponding oxide precursors under a high-temperature NH 3 atmosphere, causing an increase in the defect density and a decrease in photocatalytic activity. To improve the photocatalytic activity by reducing the defect density and improving the crystallinity, we here demonstrate an NH 3 -assisted KCl flux growth approach for the direct synthesis of the BaTaO 2 N crystals. The effects of various fluxes, solute concentration, and reaction time and temperature on the phase evolution and morphology transformation of the BaTaO 2 N crystals were systematically investigated. By changing the solute concentration from 10 to 50 mol %, it was found that phase-pure BaTaO 2 N crystals could only be grown with the solute concentrations of ≥ 10 mol % using the KCl flux, and the solute concentration of 10 mol % was solely favorable to directly grow cube-like BaTaO 2 N crystals with an average size of about 125 nm and exposed {100} and {110} faces at 950 °C for 10 h. The time-and temperature-dependent experiments were also performed to postulate the direct growth mechanisms of cube-like BaTaO 2 N submicron crystals. The BaTaO 2 N crystals modified with Pt and CoO x nanoparticles showed a reasonable H 2 and O 2 evolution, respectively, due to a lower defect density and higher crystallinity achieved by an NH 3 -assisted KCl flux method.

This paper presents a point cloud downsampling algorithm for fast and accurate trajectory optimization based on global registration error minimization. The proposed algorithm selects a weighted subset of residuals of the input point cloud such that the subset yields exactly the same quadratic point cloud registration error function as that of the original point cloud at the evaluation point. This method accurately approximates the original registration error function with only a small subset of input points (29 residuals at a minimum). Experimental results using the KITTI dataset demonstrate that the proposed algorithm significantly reduces processing time (by 87%) and memory consumption (by 99%) for global registration error minimization while retaining accuracy.

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High quality LiCoO 2 crystals, useful as cathode material for lithium-ion rechargeable batteries, were successfully grown at a holding temperature of 800-1000 °C using the NaCl flux cooling method. The morphology, structure, size uniformity, and crystallinity of the obtained LiCoO 2 crystals were obviously dependent on the growth conditions, such as the holding temperature and the starting composition. Well-developed, highly crystalline LiCoO 2 crystals were first grown at a holding temperature of 900 °C from a NaCl flux. The grown LiCoO 2 crystals had a hexagonal barrel-shaped structure with welldeveloped {001}, {104}, {101}, and {102} faces. On the basis of the powder X-ray diffraction data, the lattice parameters of the crystals were determined as a = 2.816 and c = 14.077 A ˚. These values agree approximately with those from the literature (a = 2.816 and c = 14.052 A ˚). The average crystal size was about 1.4 μm, which is a relatively small size when compared to previous reports. Transmission electron microscopy images indicate that the LiCoO 2 crystals were of very good crystallinity. It was confirmed that the charge and discharge capacities of the lithium-ion rechargeable batteries containing the grown LiCoO 2 crystals were 138 and 130 mAh 3 g -1 , respectively, values that correspond to the available capacity of 137.5 mAh 3 g -1 . The discharge capacity of the grown LiCoO 2 crystal is greater at 10 C than that of commercially available crystals.