- Method for Improving Solar Energy Conversion Efficiency Using Metal Oxide Photocatalysts having Energy Band of Core-Shell for infrared ray Visible Light Absorption and Photocatalysts Thereof

摘要

The present invention relates to a method for improving efficiency of solar energy conversion by using metal oxide photocatalysts having a core-shell energy band for infrared ray and visible light absorption, and photocatalysts. The method for improving efficiency of solar energy conversion by using metal oxide photocatalysts having a core-shell energy band comprises: a first step of forming a thin film of metal oxide nano-particles; a second step of preparing core-shell metal oxides by performing plasma reaction on the metal oxide nano-particles in a hydrogen-nitrogen atmosphere; and a third step of preparing energy conversion photocatalysts by attaching transition metals onto surfaces of the core-shell metal oxide nano-particles. The core-shell metal oxide nano-particles form a large number of oxygen holes in a shell region, thereby improving capability to transfer electron-hole pairs excited by light radiated from a core and extending a light absorption region to a visible ray region due to a change in a band gap structure. In terms of chemistry, reactivity on surfaces thereof are maximized, there enabling the core-shell metal oxide nano-particles to be used as catalysts capable of decomposing water and converting carbon dioxide by using optical energy. Furthermore, by using the photocatalysts of the third step, C1 compounds, such as methanol, methane, carbon monoxide, formic acid, etc., can be prepared through photochemical reaction inside a reactor in which carbon dioxide and water are saturated and sealed.