The photocatalyst component is installed in an air conditioning system, and is combined with a lamp to release the photocatalyst, and sterilizes the air passing through the input/output, mainly on a cover at the position of the ceiling and the air inlet, including a plurality of combinations. The assembly is internally provided with a plurality of channels extending side by side opposite to the opposite end, and at least one set of opposite end positions is respectively provided with a combination portion, and a channel surface is formed on the inner side of the channel to form a photocatalyst coating layer; wherein, the plurality of assemblies are One of the combined portions can be coupled to the other of the combined portions along at least one of the three axes, thereby increasing at least one of the length, width or height of the photocatalyst assembly to enable coverage of the various different sizes of cover The size of the set, and can increase or decrease the time of air contact with the photocatalyst coating, effectively enhancing the effect of air purification.本創作光觸媒組件安裝在空調系統,並配合一燈具照射來釋放光觸媒,對過輸入/輸出經過的空氣進行殺菌,主要是設在一位在天花板出、入風口位置的護蓋上,包含複數組合件,該組合件內部設有複數朝向相反端延伸並排的通道,且外部至少一組相反端位置分別設有組合部,又通道內側設有一表面形成光觸媒塗層的壁面;其中,複數組合件其中一者的組合部能夠沿著三軸的其中至少一軸方向連接到另一者的組合部,藉以增加光觸媒組件的長度、寬度或高度的其中至少一者,使其能夠達到覆蓋各種不同尺寸護蓋的設定大小,並能自行增減空氣接觸光觸媒塗層的時間,有效增強空氣清淨的效果。