Yusuke Asakura

Polymer carbon nitride (PCN), as an affordable and easily prepared photocatalyst, has acquired extensive attention for hydrogen production. However, bulk carbon nitride material exhibits poor dispersibility in water due to the relatively inert surface which limits its quantum efficiency in photocatalytic hydrogen production. In this study, a hydrophilic carbon nitride (HCN) is successfully synthesized by a novel salt-assisted heating process. The heightened water adsorption capacity may contribu

Gallium oxynitride (GaON) nanoparticles were synthesized through three steps; (i) hydrothermal treatment of an aqueous solution containing Ga(NO₃)₃, hexamethylenetetramine (HMT), and acetylene black, (ii) calcination, and (iii) nitridation. The presence of acetylene black in the hydrothermal treatment is effective for the synthesis of Ga₂O₃ nanoparticles after the calcination. The intermediate obtained after the hydrothermal reaction possessed no detec

Palladium (Pd), a rare and precious metal, is highly valued due to its non-renewable nature and significant cost. Therefore, recovering palladium from industrial wastewater is of great importance but remains a challenge. Herein, a composite aerogel adsorbent has been developed by linking a bipyridine covalent organic framework, termed TpBpy, with chitosan (CS) through robust covalent bonds. The resulting TpBpy/CS aerogel is employed for the selective separation and recovery of palladium at low c

In the context of achieving carbon neutrality, converting lignin-derived molecules into high-value products through photocatalytic technology provides an environmentally friendly pathway. Establishing energy-efficient processes for converting lignin derivatives requires the construction of highly active and selective photocatalysts. However, enhancing the efficiency and selectivity of photocatalysts for lignin degradation poses an ongoing challenge due to discrepancies in the redox potential and

Quaternary zinc germanium oxynitride (Zn_1+xGe)(N₂O_x), a solid solution between ZnGeN₂ and ZnO with a wurtzite structure, is one of the attractive photocatalysts under visible-light irradiation. In this study, the synthesis of (Zn_1+xGe)(N₂O_x) nanoparticles was achieved by the nitridation of Zn₂GeO₄ nanoparticles designed precisely to enhance their photocatalytic NO_x decomposition activity

AST-type zeolite with a plate morphology can be synthesized by topotactic conversion of a layered silicate (β-helix-layered silicate; HLS) by using N,N-dimethylpropionamide (DPA) to control the layer stacking of silicate layers and the subsequent interlayer condensation. Treatment of HLS twice with 1) hydrochloric acid/ethanol and 2) dimethylsulfoxide (DMSO) are needed to remove interlayer hydrated Na ions and tetramethylammonium (TMA) ions in intralayer cup-like cavities (intracavity TMA ions),

The introduction of GaN as a hole-blocking layer for a particulate Ta₃N₅ photoelectrode led to the enhancement of photoelectrochemical water oxidation.

Various types of coating films were obtained from hydrothermally synthesized Nb-doped TiO₂ (NTO) and Cs _x WO₃ (CWO) nanoparticles. The coating films possessed multifunctionality including near infrared (NIR) absorption and photocatalysis abilities. The NTO and CWO nanoparticles were synthesized by a unique solvothermal reaction in which water induced by an esterification reaction between alcohol and carboxylic acid can act as a hydrolyzing agent for metal precurs

A novel crystalline microporous material is synthesized by silylation of layered silicate RUB-51 with tetrachlorosilane (SiCl4), hydrolysis, and heat treatment for interlayer condensation. One SiCl4 molecule first undergoes ordered silylation with two confronting groups, Si–O– and Si–OH, on the interlayer surfaces of RUB-51 (bidentate silylation). Hydrolysis of the unreacted Si–Cl groups of the immobilized silyl groups by a mixture of H2O and dimethyl sulfoxide (DMSO) affords geminal Si–OH group

We demonstrate that the separation of two stages of interlayer condensation under refluxing and elimination of organic guests provides the optimal conditions for the formation of RWR-type zeolite from layered octosilicate. The obtained RWR-type zeolite has higher quality than any other RWR-type zeolite reported previously.