Tokyo University of Science

About: Tokyo University of Science is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Catalysis & Thin film. The organization has 15800 authors who have published 24147 publications receiving 438081 citations. The organization is also known as: Tōkyō Rika Daigaku & Science University of Tokyo.

Quantitative and Reversible Lectin-Induced Association of Gold Nanoparticles Modified with α-Lactosyl-ω-mercapto-poly(ethylene glycol)

Abstract: Gold nanoparticles (1−10 nm size range) were prepared with an appreciably narrow size distribution by in situ reduction of HAuCl4 in the presence of heterobifunctional poly(ethylene glycol) (PEG) derivatives containing both mercapto and acetal groups (α-acetal-ω-mercapto-PEG). The α-acetal-PEG layers formed on gold nanoparticles impart appreciable stability to the nanoparticles in aqueous solutions with elevated ionic strength and also in serum-containing medium. The PEG acetal terminal group was converted to aldehyde by gentle acid treatment, followed by the reaction with p-aminophenyl-β-d- lactopyranoside (Lac) in the presence of (CH3)2NHBH3. Lac-conjugated gold nanoparticles exhibited selective aggregation when exposed to Recinus communis agglutinin (RCA120), a bivalent lectin specifically recognizing the β-d-galactose residue, inducing significant changes in the absorption spectrum with concomitant visible color change from pinkish-red to purple. Aggregation of the Lac-functionalized gold nanoparticle...

Photocatalytic reduction of carbon dioxide over Ag cocatalyst-loaded ALa4Ti4O15 (A = Ca, Sr, and Ba) using water as a reducing reagent.

Abstract: Ag cocatalyst-loaded ALa4Ti4O15 (A = Ca, Sr, and Ba) photocatalysts with 3.79–3.85 eV of band gaps and layered perovskite structures showed activities for CO2 reduction to form CO and HCOOH by bubbling CO2 gas into the aqueous suspension of the photocatalyst powder without any sacrificial reagents. Ag cocatalyst-loaded BaLa4Ti4O15 was the most active photocatalyst. A liquid-phase chemical reduction method was better than impregnation and in situ photodeposition methods for the loading of the Ag cocatalyst. The Ag cocatalyst prepared by the liquid-phase chemical reduction method was loaded as fine particles with the size smaller than 10 nm on the edge of the BaLa4Ti4O15 photocatalyst powder with a plate shape during the CO2 reduction. CO was the main reduction product rather than H2 even in an aqueous medium on the optimized Ag/BaLa4Ti4O15 photocatalyst. Evolution of O2 in a stoichiometric ratio (H2+CO:O2 = 2:1 in a molar ratio) indicated that water was consumed as a reducing reagent (an electron donor) fo...

Surface Modification of CoO(x) Loaded BiVO₄ Photoanodes with Ultrathin p-Type NiO Layers for Improved Solar Water Oxidation.

Abstract: Photoelectrochemical (PEC) devices that use semiconductors to absorb solar light for water splitting offer a promising way toward the future scalable production of renewable hydrogen fuels. However, the charge recombination in the photoanode/electrolyte (solid/liquid) junction is a major energy loss and hampers the PEC performance from being efficient. Here, we show that this problem is addressed by the conformal deposition of an ultrathin p-type NiO layer on the photoanode to create a buried p/n junction as well as to reduce the charge recombination at the surface trapping states for the enlarged surface band bending. Further, the in situ formed hydroxyl-rich and hydroxyl-ion-permeable NiOOH enables the dual catalysts of CoO(x) and NiOOH for the improved water oxidation activity. Compared to the CoO(x) loaded BiVO4 (CoO(x)/BiVO4) photoanode, the ∼6 nm NiO deposited NiO/CoO(x)/BiVO4 photoanode triples the photocurrent density at 0.6 V(RHE) under AM 1.5G illumination and enables a 1.5% half-cell solar-to-hydrogen efficiency. Stoichiometric oxygen and hydrogen are generated with Faraday efficiency of unity over 12 h. This strategy could be applied to other narrow band gap semiconducting photoanodes toward the low-cost solar fuel generation devices.