▎ 摘　　要

NOVELTY - The device has a substrate on which a photocatalyst (2) and a water collecting and releasing material (3) are attached. A heating system heats water collecting and releasing material. A light source device is arranged on a side of the substrate. The light source device irradiates the photocatalyst. The water collecting and releasing material is selected as hygroscopic photothermal organic gel. The light source device selected as an UV light source and/or a visible light source. The heating system comprises a heating component that is directly or indirectly connected to the substrate. A graphene layer (4) is attached on the substrate. USE - Photocatalyst purifying device for use in an air purifier (Claimed). ADVANTAGE - The device allows the water collecting and releasing material to collect water in the air at normal temperature so that water vapor can be utilized as the carrier of the strong oxidizing substance when the water vapor is radiated. The device allows strong oxidizing substance to be attached on the water vapor through the diffusion of the water vapor, thus increasing purifying area of the strong oxidizing substance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an air purifying method. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a photocatalyst purifying device. Photocatalyst (2) Water collecting and releasing material (3) Graphene layer (4)