Yasuo Nishimura

Synthesis and electrochemical properties of lithium molybdenum oxides

Abstract Layered oxides Li2MoO3 were synthesized at 923 K (sample A), 1023 K (sample B), and 1073 K (sample C) and characterized by X-ray diffractometry, magnetic and electrochemical measurements. All Li2MoO3 showed rhombohedral symmetry with an α-NaFeO2-related structure and paramagnetic behavior down to 83 K. Lithium deintercalation from samples B and C proceeded to x=1.2 in Li2−xMoO3. The Li/Li2MoO3 (samples B and C) cells showed cycling capacities of 150 mAh/g in the voltage range of 1.5–4.3 V after 10 cycles. Samples B and C showed better cycle reversibility than sample A. The different charge and discharge characteristics between samples A-C might be caused by structural differences which were indicated by X-ray diffraction measurements.

Analysis of dyestuff degradation products by capillary electrophoresis.

Capillary electrophoresis (CE) with two different detection methods, mass spectrometry (MS) and UV absorption spectroscopy with photodiode array detection (UV/DAD), was used for the analysis of the degradation products of dyestuffs. We have studied wet oxidation with solid catalyst as the treatment method of wastewaters containing dyestuffs. When the Orange II (C.I. Acid Orange 7) solution was used as the model wastewater, treated solution contained unknown highly polar degradation products. We were able to determine the molecular masses of some products by CE-MS. From this clue, we tried to identify these products by CE-UV/DAD. By means of the comparison of the migration time and UV spectra of standard samples, three degradation products were identified. The separation of degradation products was successful within 15 min.

Solid polymer electrolyte CO2 reduction

Abstract Solid polymer electrolyte was applied to CO 2 reduction. A zero-gap system with an anion exchange membrane and a porous PTFE sheet deposited solid electrolyte, and a water supply system from the anodic side by back-diffusion through the membrane were effective in the reaction.

Preparation of a Gas Diffusion Electrode by Ozone Gas Pretreatment and an Ion-exchange Method

Surface oxidation using ozone gas, produced by an electrolytic ozone generator, was applied for preparation of a gas-diffusion electrode (GDE) for an electrochemical energy conversion system. An uncatalyzed carbon sheet containing poly(tetrafluoroethylene) binder was first placed into contact with ozone gas to form active functional groups on the surface of the carbon; then ion-exchange between a weakly bound hydrogen of the functional groups and a platinum cation complex was performed. A GDE having highly dispersed particles of a platinum metal deposited on a porous carbon sheet ws developed by this method. The fuel cell using this GDE showed high performance.

Effects of Bath Condition on Plating Rate of Electroless Ni Films Prepared by Reducing Agent Permeation Method

The effects of such bath conditions as reducing agent concentration, Ni salt concentration and plating temperature on the rate of electroless Ni plating by the reducing agent permeation method were examined.At the initial nucleus formation stage, it was supposed that the mutual diffusion of BH4- and Cl- through the membrane was the rate determining step and the initial nucleus formation rate was proportional to the 0.2 power of NaBH4 concentration and NiCl2 concentration. The activation energies of the diffusion coefficients of both anious were calculated to be 4.57kJ/mol.At the Ni growth stage, it was estimated that in addition to the nutual anion diffusion, Ni diffusion was also the rate determining step.The rate of Ni growth was proportional to the 0.3 power of the NaBH4 concentration and the 0.7 power of the NiCl2 concentration. The activation energy of the rate constant was calculated to be 3.90kJ/mol. The rate of Ni growth can be controlled by these kinetic parameters.