The reduction in weight of rice hull charcoal with adsorbed cesium and strontium was examined in this study. It was carefully examined whether the adsorbed cesium and strontium volatilized during the weight loss process. By heating the charcoal that had adsorbed cesium and strontium to 400 °C in air, we achieved a weight reduction of approximately 28%. The amount of cesium and strontium present in the gas that volatilized during heating was quantified. The value obtained was below the detection limit of the atomic absorption spectrometer. From the obtained results, it was found that rice hull charcoal with adsorbed cesium and strontium can undergo weight reduction on being heated, without volatilizing the adsorbed metal.

  Room temperature ionic liquids are composed of only ions and have been widely applied in various fields. DNA double helix, which is a genetic material, has been expected its application in chiral material science and electrochemistry as a natural chiral supramolecule. However, it is difficult to use DNA double helix as a material due to its insolubility in organic solvents. Herein, we studied the construction of the double helical DNA and the expression of its functions in ionic liquids. Hydrophilic ionic liquids containing water can dissolve DNA, and C-form DNA double helix, whose structure is different from that in water, was formed with increase the proportion of the ionic liquids. The water-insoluble porphyrin, THPP, can also interact with DNA double helix in the ionic liquid solution, and its induced CD signals by chiral DNA double helix indicated that THPP bound to DNA with different modes depending on the structure of ionic liquids. Construction of DNA double helix in ionic liquids, which are functional solvent themselves, enables the utilization of DNA as a functional material.

Carbon materials derived from woody biomass are considered to be a candidate of the support materials in catalytic and electrochemical reactions, which is essential for various renewable energy systems. Herein, we investigate the influence of thermal treatment on the structure and chemical composition of copper-loaded woody-derived carbon materials. The thermal treatment method for carbonizing the woody biomass and the species of copper impregnated on their surface strongly affected the structure and porosity of the as-synthesized carbon materials and the size of the loaded-copper particles. Moreover, the chemical composition of loaded-copper species significantly depended on the thermal treatment for copper impregnation. This study provides insights into synthetic methods for metal-loaded carbon materials (especially woody biomass) with high surface area, controllable chemical composition of metal content, and metal particle size.

CaO-ZnO-P₂O₅ bioglasses were synthesized in order to study the relationship between their composition and in vitro behavior. We specifically examined the relationship between the P₂O₅ content and the in vitro behavior of the powder compacts. The weight gain percentage after immersion in a simulated body fluid (SBF) for a 4-week-period increased with the increase in P₂O₅ content up to a certain threshold, and the maximum weight gain was observed when the P₂O₅ content was 33.6 mol%. As the amount of P₂O₅ increased further, the weight gain in the samples rapidly turned to a negative value. In other words, it was found that there was a threshold for the P₂O₅ content. In the sample that had the maximum weight gain, submicron level, round precipitates were observed after the SBF test and presumed to be an amorphous calcium-zinc phosphate substance. Furthermore, a phosphate glass structure that promotes the precipitation of the above substances was proposed. The structure was formed when the long-chain structure of P-O (Q² group), which promotes the dissolution of the P component, and the short-chain structure of P-O (Q⁰ and Q¹ groups), which are considered to be the starting points of precipitation, coexist in a well-balanced ratio within the glass.

We successfully synthesized K-substituted NBT, (Na_1-yK_y)_0.5Bi_0.5TiO₃, powder samples using the polymerizable complex method. Rietveld analysis of the powder X-ray diffraction (XRD) data for the samples revealed that a morphotropic phase boundary (MPB) is located at a K content of y = 0.29 on K-substituted NBT synthesized with suppressing evaporation of bismuth and sodium.

The spinel solid solutions in pseudo-ternary LiNi₂O_x-LiMn₂O₄-LiTi₂O_x system were synthesized systematically by using combinatorial synthesis technique based on the electrostatic spray deposition. The product phase and its electrode properties were mapped. The spinel phase was mainly obtained in the range of x < 0.5 and y < 0.5 in LiNi_xMn_1-x-yTi_yO₄. The charge-discharge plateau capacity at around 4.7 V increased with increase Ni content. The discharge capacity and cycling performance were improved by substitution of Ti until y = 0.3 but reduced by further substitution. LiNi_0.5Mn_1.3Ti_0.2O₄ exhibited the best electrode properties of first discharge capacity of 123 mAh/g, capacity retention after 100 cycle of 88 %, and rate performance better then Ti non-substituted sample.

In our study, we fabricated Ta₃N₅ and ZnO composite-type photoanodes using the roll press method. Compared with the pristine Ta₃N₅ photoanode, the composite photoanodes exhibited better optical and photoelectrochemical properties, especially at low electrode potential. These results could have come from the high visible-light transparency of the ZnO and the formation of a heterojunction between the Ta₃N₅ and the ZnO. This fabrication process could be applied to other materials.