Abstract:
The present invention discloses a method for improving solar energy conversion efficiency using metal oxide photocatalysts having an energy band of core-shell structure for ultraviolet (UV) ray and visible light absorption, comprising a first process of forming a nanoparticle thin film layer; a second process of preparing a core-shell metal oxide on metal oxide nanoparticles by a plasma reaction under a hydrogen and nitrogen gas atmosphere, and a third process of depositing a transition metal on surfaces of core-shell metal oxide nanoparticles to produce a photocatalyst for energy conversion. A great amount of oxygen vacancies is formed in a shell region by the core-shell metal oxide to achieve effects of improving transfer ability of electron-hole pairs excited by light, and extending a wavelength range of absorbable light to a visible light region by changing a band-gap structure.
Abstract:
Disclosed is a method for improving solar energy conversion efficiency of a metal oxide semiconductor photocatalyst, which includes rapidly performing hydrogenation and nitrogenation of a metal oxide semiconductor material through an H2/N2 mixed gas plasma treatment in a single process at room temperature, so as to enhance photocatalytic energy conversion efficiency. Specifically, disclosed is a treatment technique in which a plasma ball formed by controlling a mixing ratio of hydrogen gas to nitrogen gas in a range of 1:1 to 1:3 contacts with a surface of a metal oxide material, such that a great amount of oxygen vacancy and nitrogen elements are introduced in the surface of the metal oxide material to improve electron-hole pairs transfer ability thereof and decrease a size of the band-gap. A catalyst including the metal oxide material directly converts the solar energy into a compound by photocatalytic hydrogen generation and CO2 conversion.