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  2. Photocatalytic water splitting - Wikipedia

    en.wikipedia.org/wiki/Photocatalytic_water_splitting

    The process of water-splitting is a highly endothermic process (ΔH > 0). Water splitting occurs naturally in photosynthesis when the energy of four photons is absorbed and converted into chemical energy through a complex biochemical pathway (Dolai's or Kok's S-state diagrams). [3] O–H bond homolysis in water requires energy of 6.5 - 6.9 eV ...

  3. Light-dependent reactions - Wikipedia

    en.wikipedia.org/wiki/Light-dependent_reactions

    This is the second core process in photosynthesis. The initial stages occur within picoseconds, with an efficiency of 100%. The seemingly impossible efficiency is due to the precise positioning of molecules within the reaction center. This is a solid-state process, not a typical chemical reaction. It occurs within an essentially crystalline ...

  4. Photocatalysis - Wikipedia

    en.wikipedia.org/wiki/Photocatalysis

    2 surfaces that were plasma etched for 10 seconds and subsequent surface modifications with ODP showed a water contact angle greater than 150 . The surface was converted into a superhydrophilic surface (water contact angle = 0 ) upon UV illumination, due to rapid decomposition of octadecylphosphonic acid coating resulting from TiO 2 photocatalysis.

  5. Water splitting - Wikipedia

    en.wikipedia.org/wiki/Water_splitting

    In thermolysis, water molecules split into hydrogen and oxygen. For example, at 2,200 °C (2,470 K; 3,990 °F) about three percent of all H 2 O are dissociated into various combinations of hydrogen and oxygen atoms, mostly H, H 2, O, O 2, and OH. Other reaction products like H 2 O 2 or HO 2 remain minor. At the very high temperature of 3,000 ...

  6. Photosynthesis - Wikipedia

    en.wikipedia.org/wiki/Photosynthesis

    Photosynthesis changes sunlight into chemical energy, splits water to liberate O 2, and fixes CO 2 into sugar. Most photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from carbon dioxide and water using energy from light.

  7. Photosystem II - Wikipedia

    en.wikipedia.org/wiki/Photosystem_II

    In 2011 the OEC of PSII was resolved to a level of 1.9Å revealing five oxygen atoms serving as oxo bridges linking the five metal atoms and four water molecules bound to the Mn 4 CaO 5 cluster; more than 1,300 water molecules were found in each photosystem II monomer, some forming extensive hydrogen-bonding networks that may serve as channels ...

  8. Oxygen-evolving complex - Wikipedia

    en.wikipedia.org/wiki/Oxygen-evolving_complex

    The oxygen-evolving complex (OEC), also known as the water-splitting complex, is a water-oxidizing enzyme involved in the photo-oxidation of water during the light reactions of photosynthesis. [3] OEC is surrounded by 4 core proteins of photosystem II at the membrane-lumen interface.

  9. Photosystem - Wikipedia

    en.wikipedia.org/wiki/Photosystem

    The antenna complex contains hundreds of chlorophyll molecules which funnel the excitation energy to the center of the photosystem. At the reaction center, the energy will be trapped and transferred to produce a high energy molecule. [2] The main function of PSII is to efficiently split water into oxygen molecules and protons.