水分解によるソーラー水素製造に向けた銅カルコゲナイド系光カソードに関する研究

学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 堂免 一成, 東京大学教授 山田 淳夫, 東京大学准教授 牛山 浩, 東京大学准教授 辻 佳子, 東京大学准教授 Jean-Jacques DELAUNAY, 東京大学准教授 久保田 純University of Tokyo(東京大学

マクロファージからのリポポリサッカライド誘導NO産生に対するAsp-hemolysin関連合成ペプチドP-21の影響

To clarify the effect of Asp-hemolysin-related synthetic peptide (P-21) on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in murine peritoneal macrophages (Mφ) was demonstrated this study. P-21 inhibited LPS (from Escherichia coli O111 : B4) -induced NO production of Mφ in a dose-dependent manner. P-21 slightly effected on NO production induced by LPS from Klebsiella pneumonias in Mφ. The inhibition ability of the P-21 was influenced by differences of LPS from various strains. These results suggest that P-21 has effects on the bioactivity of LPS, such as NO production in Mφ

数種の内分泌攪乱化学物質のマウス腹腔マクロファージ細胞機能に及ぼす影響

We investegated the effects of nine possible endocrine disrupting chemicals (EDCs) on the nitric oxide (NO) production and growth of mouse peritoneal macrophages. Genistein and coumestrol inhibited lipopolysaccharide-induced NO production in macrophages, whereas other EDCs had no effect. In WST-8 assay, the growth of mouse macrophages was induced by 17β-estradiol, bisphenol A, nonylphenol, diethyl phthalete, genistein and daidzein. In addition, the cell viability of daidzein-treated macrophages was 1.7-fold increased as compared with non-treated macrophages. These results suggest that EDCs affect cellular function in macrophages

[Viakoto Mikami Static and Dynamic Characteristics of Rolling-Pad Journal Bearings in Super-Laminar Flow Regime

Static and dynamic characteristics of load-o

Hybrid photocathode consisting of a CuGaO2 p-type semiconductor and a Ru(ii)–Re(i) supramolecular photocatalyst: non-biased visible-light-driven CO2 reduction with water oxidation

A CuGaO2 p-type semiconductor electrode was successfully employed for constructing a new hybrid photocathode with a Ru(II)–Re(I) supramolecular photocatalyst (RuRe/CuGaO2). The RuRe/CuGaO2 photocathode displayed photoelectrochemical activity for the conversion of CO2 to CO in an aqueous electrolyte solution with a positive onset potential of +0.3 V vs. Ag/AgCl, which is 0.4 V more positive in comparison to a previously reported hybrid photocathode that used a NiO electrode instead of CuGaO2. A photoelectrochemical cell comprising this RuRe/CuGaO2 photocathode and a CoOx/TaON photoanode enabled the visible-light-driven catalytic reduction of CO2 using water as a reductant to give CO and O2 without applying any external bias. This is the first self-driven photoelectrochemical cell constructed with the molecular photocatalyst to achieve the reduction of CO2 by only using visible light as the energy source and water as a reductant

Photoelectrochemical Reduction of CO2 Coupled to Water Oxidation Using a Photocathode With a Ru(II)-Re(I) Complex Photocatalyst and a CoOx/TaON Photoanode.

International audiencePhotoelectrochemical CO2 reduction activity of a hybrid photocathode, based on a Ru(II)-Re(I) supramolecular metal complex photocatalyst immobilized on a NiO electrode (NiO-RuRe) was confirmed in an aqueous electrolyte solution. Under half-reaction conditions, the NiO-RuRe photocathode generated CO with high selectivity, and its turnover number for CO formation reached 32 based on the amount of immobilized RuRe. A photoelectrochemical cell comprising a NiO-RuRe photocathode and a CoOx/TaON photoanode showed activity for visible-light-driven CO2 reduction using water as a reductant to generate CO and O2, with the assistance of an external electrical (0.3 V) and chemical bias (0.10 V) produced by a pH difference. This is the first example of a molecular and semiconductor photocatalyst hybrid-constructed photoelectrochemical cell for visibl-light-driven CO2 reduction using water as a reductant

Photoelectrochemical CO₂ Reduction Using a Ru(II)–Re(I) Supramolecular Photocatalyst Connected to a Vinyl Polymer on a NiO Electrode

A Ru­(II)–Re­(I) supramolecular photocatalyst and a Ru­(II) redox photosensitizer were both deposited successfully on a NiO electrode by using methyl phosphonic acid anchoring groups and the electrochemical polymerization of the ligand vinyl groups of the complexes. This new molecular photocathode, <i>poly</i>-RuRe/NiO, adsorbed a larger amount of the metal complexes compared to one using only methyl phosphonic acid anchor groups, and the stability of the complexes on the NiO electrode were much improved. The <i>poly</i>-RuRe/NiO acted as a photocathode for the photocatalytic reduction of CO₂ at <i>E</i> = −0.7 V vs Ag/AgCl under visible-light irradiation in an aqueous solution. The <i>poly</i>-RuRe/NiO produced approximately 2.5 times more CO, and its total Faradaic efficiency of the reduction products improved from 57 to 85%

Photoelectrochemical Hydrogen Evolution from Water Using Copper Gallium Selenide Electrodes Prepared by a Particle Transfer Method

Photocathodes prepared using p-type semiconductor photocatalyst powders of copper gallium selenides (CGSe) were investigated for visible-light-driven photoelectrochemical water splitting. The CGSe powders were prepared by solid-state reaction of selenide precursors with various Ga/Cu ratios. The CGSe photoelectrodes prepared by the particle transfer method showed cathodic photocurrent in an alkaline electrolyte. Pt modification was conducted for all the photoelectrodes by photoassisted electrodeposition. CGSe particles with a Ga/Cu ratio of 2, consisting of the CuGa₃Se₅ phase and an intermediate phase between CuGaSe₂ and CuGa₃Se₅, yielded the largest cathodic photocurrent. By surface modification with a CdS semiconductor layer, the photocurrent density and onset potential clearly increased, indicating enhancement of charge separation caused by the formed p-n junction with appropriate band alignment at solid–liquid interfaces. A multilayer structure on the particles was confirmed to be beneficial for enhancing the photocurrent, as in the case of thin-film photoelectrodes. A Pt/CdS/CGSe electrode (Ga/Cu = 2) was demonstrated to work as a photocathode contributing stoichiometric hydrogen evolution from water for 16 h under visible light irradiation

Photoelectrochemical Solar Cells Consisting of a Pt-Modified CdS Photoanode and an Fe(ClO₄)₂/Fe(ClO₄)₃ Redox Shuttle in a Nonaqueous Electrolyte

Photoelectrochemical photovoltaic cells (PEC PVs) consisting of an n-type CdS single-crystal electrode and a Pt black counter electrode in a nonaqueous electrolyte containing an Fe­(ClO₄)₂/Fe­(ClO₄)₃ redox shuttle were studied as a means of obtaining photovoltages above the onset voltage for water splitting with one-step photoexcitation. To improve the photovoltaic performance, the effects of the redox concentration on the cell performance were investigated by UV–vis absorption and PEC measurements and by assessing the electrolyte using hydrodynamic voltammetry. Under visible-light irradiation (420–800 nm) from a Xe lamp, a relatively high open-circuit voltage (<i>V</i>_OC) of approximately 1.6 V was obtained, resulting from the negative flat-band potential of the CdS and the positive redox potential of the Fe complexes. Upon optimization of the redox concentration, photocurrent for the Pt/CdS electrode was increased to approximately 30 mA cm^–2, and an incident photon-to-current conversion efficiency of up to 80% was achieved at 480 nm as a result of the promotion of the anodic reaction on the Pt surface. Under simulated sunlight, the PEC PV composed of Pt/CdS in a 20 mM Fe­(ClO₄)₂/Fe­(ClO₄)₃ electrolyte exhibited a <i>V</i>_OC of 1.38 V, a 3.54 mA cm^–2 short-circuit current, and a 2.8% photon-to-energy conversion efficiency