Abstract: A production method for producing a hydrogen gas through electrolysis of water is provided. The production method includes: decreasing a current density to a range that is greater than 0 A/cm2 and less than a value used in the electrolysis and in which the electrolysis does not stop; holding the current density for 1 second or more while introducing a gas to at least a hydrogen generating electrode; and decreasing the current density to a value at which the electrolysis does not take place so as to stop the electrolysis. It is preferable that the gas is a gas that is electrochemically inert to a fuel cell reaction. It is also preferable that the gas is at least one selected from the group consisting of nitrogen and a noble gas.

Abstract: An electrode catalyst is provided in which degradation of catalytic action over time is suppressed. The electrode catalyst includes a mesoporous carbon support having pores, and catalyst metal particles supported in at least some of the pores. The ratio r/R of the mean particle size r of the catalyst metal particles to the modal pore size R of the pores is from 0.01 to 0.6, and the mean particle size r is 6 nm or less. The modal pore size R of the pores is preferably from 2 to 50 nm.

Abstract: An electrode catalyst layer for a fuel cell includes a catalyst/support composite including a support and a catalyst supported thereon. The support contains a titanium oxide. The surface of the catalyst/support composite has an oxide of at least one element selected from the group consisting of niobium, tantalum, zirconium, and silicon. The ratio A2/A1 is from 0.35 to 1.70, wherein A1 is the atomic ratio of titanium on a surface of the catalyst layer and A2 is the atomic ratio of a total of niobium, tantalum, zirconium, and silicon on the surface of the catalyst layer, A1 and A2 being measured by X-ray photoelectron spectroscopy. The titanium oxide preferably has a composition TiOx (0.5 ? x < 2).

Abstract: A catalyst layer for a fuel cell contains a support and a catalyst supported on the support. The support contains a titanium oxide having a crystal phase of Ti2O. The ratio of total abundance of trivalent Ti and divalent Ti (W2) to abundance of tetravalent Ti (W1), W2/W1, is 0.1 or more as determined on the surface of the catalyst layer by X-ray photoelectron spectroscopy. The catalyst is preferably made of at least one metal selected from platinum, iridium, and ruthenium, or an alloy thereof. Also, the catalyst layer for a fuel cell preferably further contains an ionomer, and the ratio of mass of the ionomer (I) to mass of the catalyst-supporting support (S), I/S, is preferably 0.06 or more and 0.23 or less.

Abstract: A toner for developing electrostatic images includes a binder, a colorant, iron, silicon, and sulfur. The colorant includes a phosphor and a non-fluorescent colorant. The phosphor includes either one or both of a nitride and an oxynitride each including an alkaline-earth metal, silicon, and an activator element. A volume average particle diameter of the phosphor is greater than or equal to about 50 nm and less than or equal to about 400 nm. An internal quantum efficiency of the phosphor at an excitation wavelength of 450 nm is greater than or equal to about 60%.

Abstract: A phosphor includes a nitride including an alkaline-earth metal element, silicon, and an activator element, wherein the phosphor has a volume average particle diameter ranging from about 50 nm to about 400 nm, and an internal quantum efficiency of greater than or equal to about 60% at an excitation wavelength of 450 nm, the phosphor is represented by a formula M2Si5N8, the M includes one or more alkaline-earth metal element selected from Ca, Sr, Ba, and Mg and including at least Sr, and one or more activator element selected from Eu and Ce and including at least Eu, an amount of the Sr included in the phosphor is about 15 mol % to about 99 mol % based on total moles of the M, and an amount of the activator element included in the phosphor is about 1 mol % to 20 mol % based on the total moles of the M.

Abstract: Disclosed is a phosphor including at least one of a nitride and an oxynitride, wherein the nitride and the oxynitride contain an alkaline-earth metal element, silicon, and an activator element. wherein the phosphor has a volume average particle diameter of greater than or equal to about 50 nm and less than or equal to about 400 nm and an inner quantum efficiency of greater than or equal to about 60% at an excitation wavelength of about 450 nm. The method of preparing a phosphor includes a precursor preparation process of preparing a phosphor precursor particles including a silicon nitride particles, a compound containing an alkaline-earth metal element, and a compound containing an activator element, wherein the compound containing an alkaline-earth metal element and the compound containing an activator element are deposited on the surface of the silicon nitride particles; and a firing process of firing the phosphor precursor particles.

Abstract: A toner for developing electrostatic images includes a binder, a colorant, iron, silicon, and sulfur. The colorant includes a phosphor and a non-fluorescent colorant. The phosphor includes either one or both of a nitride and an oxynitride each including an alkaline-earth metal, silicon, and an activator element. A volume average particle diameter of the phosphor is greater than or equal to about 50 nm and less than or equal to about 400 nm. An internal quantum efficiency of the phosphor at an excitation wavelength of 450 nm is greater than or equal to about 60%.

Abstract: A phosphor includes a nitride including an alkaline-earth metal element, silicon, and an activator element, wherein the phosphor has a volume average particle diameter ranging from about 50 nm to about 400 nm, and an internal quantum efficiency of greater than or equal to about 60% at an excitation wavelength of 450 nm, the phosphor is represented by a formula M2Si5N8, the M includes one or more alkaline-earth metal element selected from Ca, Sr, Ba, and Mg and including at least Sr, and one or more activator element selected from Eu and Ce and including at least Eu, an amount of the Sr included in the phosphor is about 15 mol % to about 99 mol % based on total moles of the M, and an amount of the activator element included in the phosphor is about 1 mol % to 20 mol % based on the total moles of the M.

Abstract: A magenta toner for developing electrostatic latent images, wherein the magenta toner includes a magenta toner particle having a polymer binder and a colorant, wherein the colorant includes a magenta pigment or dye and a visible light-excitable nitride fluorescent substance.

Abstract: Disclosed is a phosphor including at least one of a nitride and an oxynitride, wherein the nitride and the oxynitride contain an alkaline-earth metal element, silicon, and an activator element. wherein the phosphor has a volume average particle diameter of greater than or equal to about 50 nm and less than or equal to about 400 nm and an inner quantum efficiency of greater than or equal to about 60% at an excitation wavelength of about 450 nm. The method of preparing a phosphor includes a precursor preparation process of preparing a phosphor precursor particles including a silicon nitride particles, a compound containing an alkaline-earth metal element, and a compound containing an activator element, wherein the compound containing an alkaline-earth metal element and the compound containing an activator element are deposited on the surface of the silicon nitride particles; and a firing process of firing the phosphor precursor particles.

Abstract: A magenta toner for developing electrostatic latent images, wherein the magenta toner includes a magenta toner particle having a polymer binder and a colorant, wherein the colorant includes a magenta pigment or dye and a visible light-excitable nitride fluorescent substance.