Oxygen deficiency was the major limiting factor of decreasing current and voltage during dark reactions.
There was a sharp decline of current and power density during night when plants mostly undergo dark reactions.
Likewise, to study the impact of day and night circadian rhythm or diurnal cycle on PMFC performance, power and current output was measured during dark reaction duration of plants with a variation of 1 hour at 10:00 PM, 11:00 PM and 12:00 PM.
Once produced, these energy-rich compounds must then migrate to the energy transfer point in the leaf and release their energy to drive the light-independent reactions or dark reaction
in the chloroplast stoma to convert carbon dioxide into glucose through a complex series of reactions that all first-year biology students learn as the Calvin Benson cycle.
We've been able to separate the light reaction from the dark reaction
and instead of using biological photosynthesis, we are using solar panels to convert the sunlight to electrical energy, then to a chemical intermediate, and using that to power carbon dioxide fixation to produce the fuel," Liao said.
Photosynthesis consists of two basic light reactions--photolysis and photophosphorylation--followed by the dark reactions of the Calvin cycle.
In truth, the so-called dark reaction usually takes place in the presence of light, but light is not required.
Dark reactions use indirect solar absorption, such as in biomass conversion, in which exposure to sunlight is used in synthesis or catalysis reactions.
Dark reactions being studied by SERI include enzyme catalysis, electrocatalysis and heterogeneous catalysis, and homogeneous catalysis.