What is "hill reaction"

The Hill reaction was discovered by the biochemist Robin Hill from the University of Cambridge in 1937. The Hill reaction is the light-driven transfer of electrons from water to Hill reagents (non-physiological oxidants) against a chemical potential gradient. The Hill reaction demonstrated that oxygen O is produced in plants in a process that is separate from the process that converts carbon dioxide (CO) to sugars. Hill's observation made a basic underlying refinement to our modern understandings of the process of photosynthesis.