photocatalysis

noun
pho·​to·​ca·​tal·​y·​sis | \ ˌfōt-ō-kə-ˈtal-ə-səs How to pronounce photocatalysis (audio) \
plural photocatalyses\ -​ˌsēz How to pronounce photocatalyses (audio) \

Medical Definition of photocatalysis

: the acceleration of a chemical reaction by radiant energy (as light) acting either directly or by exciting a substance that in turn catalyzes the main reaction — compare photoinactivation sense 1