The two pigment system theory of photosynthesis was proposed by

The two-pigment system theory of photosynthesis was proposed by Hill.
The Hill reaction is the portion of the light reactions in which electrons from water are transferred to an electron acceptor, reducing the acceptor.
This reaction was first observed by Robert Hill in 1937 and it was he who demonstrated that isolated chloroplasts can produce O₂ in the absence of CO₂. These processes are associated with two groups of photosynthetic pigments called pigment system I and pigment system II.