Water splitting to replicate the natural process of photosynthesis, converting sunlight, water and carbon dioxide into carbohydrates and oxygen. Recently, this has been successful in splitting water into hydrogen and oxygen using an artificial compound called Nafion. High-temperature electrolysis (also HTE or steam electrolysis) is a method currently being investigated for the production of hydrogen from water with oxygen as a by-product. Other research includes thermolysis on defective carbon substrates, thus making hydrogen production possible at temperatures just under 1000 °C. The iron oxide cycle is a series of thermochemical processes used to produce hydrogen. The iron oxide cycle consists of two
Ocean storage of carbon dioxide hydrate. Two regions are defined for exploration: the negative buoyancy zone (NBZ), which is the region between liquid carbon dioxide denser than surrounding water and where liquid carbon dioxide has neutral buoyancy, and hydrate formation zone (HFZ), which typically has low temperatures and high pressures. Several research models have shown that the optimal depth of injection requires consideration of intrinsic permeability and any changes in liquid carbon dioxide permeability for optimal storage. The formation of hydrates decreases liquid carbon dioxide permeability, and injection below HFZ is more energetically favored than within the HFZ. If the NBZ is a greater column