{"id":14278,"date":"2018-11-20T19:08:13","date_gmt":"2018-11-21T00:08:13","guid":{"rendered":"https:\/\/english.cpnn-world.org\/?p=14278"},"modified":"2018-11-21T19:56:16","modified_gmt":"2018-11-22T00:56:16","slug":"researchers-develop-artificial-photosynthesis-system-that-generates-both-hydrogen-fuel-and-electricity","status":"publish","type":"post","link":"https:\/\/english.cpnn-world.org\/?p=14278","title":{"rendered":"Researchers Develop Artificial Photosynthesis System that Generates Both Hydrogen Fuel and Electricity"},"content":{"rendered":"
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. . SUSTAINABLE DEVELOPMENT . .<\/p>\n

An article by Dan McCue from the Renewable Energy Magazine<\/a><\/p>\n

Researchers at the U.S. Department of Energy\u2019s Lawrence Berkeley National Laboratory (Berkeley Lab) and the Joint Center for Artificial Photosynthesis (JCAP), a DOE Energy Innovation Hub, have come up with a new recipe for renewable fuels that could bypass the limitations in current materials: an artificial photosynthesis device called a \u201chybrid photoelectrochemical and voltaic (HPEV) cell\u201d that turns sunlight and water into not just one, but two types of energy \u2013 hydrogen fuel and electricity. The paper describing this work was published on October 29 in Nature Materials<\/a>. <\/p>\n

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\nIllustration: The HPEV cell\u2019s extra back outlet would allow the current to be split into two, so that one part of the current contributes to solar fuels generation, and the rest can be extracted as electrical power. (Credit: Berkeley Lab, JCAP)<\/center><\/p>\n

Most water-splitting devices are made of a stack of light-absorbing materials. Each layer absorbs different parts or \u201cwavelengths\u201d of the solar spectrum, ranging from less-energetic wavelengths of infrared light to more-energetic wavelengths of visible or ultraviolet light.<\/p>\n

When each layer absorbs light it builds an electrical voltage. These individual voltages combine into one voltage large enough to split water into oxygen and hydrogen fuel. But according to Gideon Segev, a postdoctoral researcher at JCAP in Berkeley Lab\u2019s Chemical Sciences Division and the study\u2019s lead author, the problem with this configuration is that even though silicon solar cells can generate electricity very close to their limit, their high-performance potential is compromised when they are part of a water-splitting device.<\/p>\n

\u201cIt\u2019s like always running a car in first gear,\u201d said Segev. \u201cThis is energy that you could harvest, but because silicon isn\u2019t acting at its maximum power point, most of the excited electrons in the silicon have nowhere to go, so they lose their energy before they are utilized to do useful work.\u201d<\/p>\n

(Article continued in the right side of the page)<\/p>\n<\/div>\n

Question for this article:<\/div>\n
<\/div>\n
\n

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How can we ensure that science contributes to peace and sustainable development?<\/a><\/p>\n

Are we making progress in renewable energy?<\/a><\/em><\/strong><\/p>\n

(Article continued from the left side of the page)<\/p>\n

So Segev and his co-authors \u2013 Jeffrey W. Beeman, a JCAP researcher in Berkeley Lab\u2019s Chemical Sciences Division, and former Berkeley Lab and JCAP researchers Jeffery Greenblatt, who now heads the Bay Area-based technology consultancy Emerging Futures LLC, and Ian Sharp, now a professor of experimental semiconductor physics at the Technical University of Munich in Germany \u2013 proposed a surprisingly simple solution to a complex problem.<\/p>\n

\u201cWe thought, \u2018What if we just let the electrons out?\u2019\u201d said Segev.<\/p>\n

In water-splitting devices, the front surface is usually dedicated to solar fuels production, and the back surface serves as an electrical outlet. To work around the conventional system\u2019s limitations, they added an additional electrical contact to the silicon component\u2019s back surface, resulting in an HPEV device with two contacts in the back instead of just one. The extra back outlet would allow the current to be split into two, so that one part of the current contributes to solar fuels generation, and the rest can be extracted as electrical power.<\/p>\n

After running a simulation to predict whether the HPEC would function as designed, they made a prototype to test their theory. \u201cAnd to our surprise, it worked!\u201d Segev said.<\/p>\n

According to their calculations, a conventional solar hydrogen generator based on a combination of bismuth vanadate and silicon will utilize only 6.8 percent of the solar energy striking the cell and store it the form of hydrogen fuel. All the rest is lost.<\/p>\n

In contrast, the HPEV cells harvest leftover electrons that do not contribute to fuel generation. These residual electrons are used to generate electrical power, resulting in a dramatic increase in the overall solar energy conversion efficiency. For example, according to the same calculations, the same 6.8 percent of the solar energy can be stored as hydrogen fuel in an HPEV cell made of bismuth vanadate and silicon, and another 13.4 percent of the solar energy can be converted to electricity. This enables a combined efficiency of 20.2 percent, three times better than conventional solar hydrogen cells.<\/p>\n

The researchers plan to continue their collaboration so they can look into using the HPEV concept for other applications such as reducing carbon dioxide emissions. \u201cThis was truly a group effort where people with a lot of experience were able to contribute,\u201d added Segev. \u201cAfter a year and a half of working together on a pretty tedious process, it was great to see our experiments finally come together.\u201d<\/p>\n

The Joint Center for Artificial Photosynthesis <\/a> is a DOE Energy Innovation Hub.<\/p>\n

The work was supported by the DOE Office of Science.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

. . SUSTAINABLE DEVELOPMENT . . An article by Dan McCue from the Renewable Energy Magazine Researchers at the U.S. Department of Energy\u2019s Lawrence Berkeley National Laboratory (Berkeley Lab) and the Joint Center for Artificial Photosynthesis (JCAP), a DOE Energy Innovation Hub, have come up with a new recipe for renewable fuels that could bypass … Continue reading Researchers Develop Artificial Photosynthesis System that Generates Both Hydrogen Fuel and Electricity<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[91,10],"tags":[5],"class_list":["post-14278","post","type-post","status-publish","format-standard","hentry","category-north-america","category-sustainable","tag-north-america"],"_links":{"self":[{"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=\/wp\/v2\/posts\/14278","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=14278"}],"version-history":[{"count":0,"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=\/wp\/v2\/posts\/14278\/revisions"}],"wp:attachment":[{"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14278"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14278"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/english.cpnn-world.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}