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Water splitting is the general term for a chemical reaction in which water is separated into oxygen and hydrogen. Efficient and economical water splitting would be a key technology component of a hydrogen economy. Various techniques for water splitting have been issued in water splitting patents in the United States.〔(Patent Database Search Results: ttl/"water splitting" in US Patent Collection )〕 In photosynthesis, water splitting donates electrons to power the electron transport chain in photosystem II. == Electrolysis == (詳細はElectrolysis of water is the decomposition of water (H2O) into oxygen (O2) and hydrogen gas (H2) due to an electric current being passed through the water. In chemistry and manufacturing, electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them. One important use of electrolysis of water or artificial photosynthesis (photoelectrolysis in a photoelectrochemical cell) is to produce hydrogen. Recently, researchers have shown that water splitting can be broken into two discrete steps using polyoxometalate based redox mediators.〔 ''Decoupled catalytic hydrogen evolution from a molecular metal oxide redox mediator in water splitting'' B. Rausch, M. D. Symes, G. Chisholm, L. Cronin, Science , 2014 , 345 , 1326-1330.〕 In power to gas the excess power or off peak power generated by wind generators or solar arrays is used for load balancing in the energy grid by injecting the hydrogen into the natural gas grid using an electrolyser. Production of hydrogen from water requires large amounts of energy and is uncompetitive with production from coal or natural gas. Potential electrical energy supplies include hydropower, wind turbines, or photovoltaic cells. Usually, the electricity consumed is more valuable than the hydrogen produced so this method has not been widely used. Other potential energy supplies include heat from nuclear reactors and light from the sun. Hydrogen can also be used to store renewable electricity when it is not needed (like the wind blowing at night) and then the hydrogen can be used to meet power needs during the day or fuel vehicles. This aspect helps make hydrogen an enabler of the wider use of renewables,〔(Electrolysis of Water )〕 and internal combustion engines. (''See hydrogen economy.'') 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「water splitting」の詳細全文を読む スポンサード リンク
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