| A method of deodorizing, antibacterial and decontamination using a plasmonic photocatalyst includes the steps as follows. A plasmonic photocatalyst is provided. The plasmonic photocatalyst and an object to be treated are made to be in contact. The plasmonic photocatalyst is made to absorb an electromagnetic wave to perform a deodorizing, antibacterial and decontamination reaction on the object to be treated, and the deodorizing, antibacterial and decontamination reaction is to perform an oxidative decomposition or removal reaction on a contaminant in the object to be treated. A wavelength of the electromagnetic wave is in a range of 300 nm to 11000 nm. A method of treating cancer is also disclosed. |