Clean Renewable Source Of Hydrogen Fuel For Electric Car

Rice University scientists have created an efficient, simple-to-manufacture oxygen-evolution catalyst that pairs well with semiconductors for solar water splitting, the conversion of solar energy to chemical energy in the form of hydrogen and oxygen.

anode RiceA photo shows an array of titanium dioxide nanorods with an even coating of an iron, manganese and phosphorus catalyst. The combination developed by scientists at Rice University and the University of Houston is a highly efficient photoanode for artificial photosynthesis. Click on the image for a larger version

The lab of Kenton Whitmire, a Rice professor of chemistry, teamed up with researchers at the University of Houston and discovered that growing a layer of an active catalyst directly on the surface of a light-absorbing nanorod array produced an artificial photosynthesis material that could split water at the full theoretical potential of the light-absorbing semiconductor with sunlight. An oxygen-evolution  catalyst splits water into hydrogen and oxygen. Finding a clean renewable source of hydrogen fuel is the focus of extensive research, but the technology has not yet been commercialized.

The Rice team came up with a way to combine three of the most abundant metalsiron, manganese and phosphorus — into a precursor that can be deposited directly onto any substrate without damaging it. To demonstrate the material, the lab placed the precursor into its custom chemical vapor deposition (CVD) furnace and used it to coat an array of light-absorbing, semiconducting titanium dioxide nanorods. The combined material, called a photoanode, showed excellent stability while reaching a current density of 10 milliamps per square centimeter, the researchers reported.

The results appear in two new studies. The first, on the creation of the films, appears in Chemistry: A European Journal. The second, which details the creation of photoanodes, appears in ACS Nano.

Source: http://news.rice.edu/

How To Turn CO2 Into Rock

An international team of scientists have found a potentially viable way to remove anthropogenic (caused or influenced by humans) carbon dioxide emissions from the atmosphereturn it into rock.

The study, published today in Science, has shown for the first time that the greenhouse gas carbon dioxide (CO2) can be permanently and rapidly locked away from the atmosphere, by injecting it into volcanic bedrock. The CO2 reacts with the surrounding rock, forming environmentally benign minerals.

turn co2 into rockCLICK ON THE IMAGE TO ENJOY THE VIDEO

Measures to tackle the problem of increasing greenhouse gas emissions and resultant climate change are numerous. One approach is Carbon Capture and Storage (CCS), where CO2 is physically removed from the atmosphere and trapped underground. Geoengineers have long explored the possibility of sealing CO2 gas in voids underground, such as in abandoned oil and gas reservoirs, but these are susceptible to leakage. So attention has now turned to the mineralisation of carbon to permanently dispose of CO2.

Until now it was thought that this process would take several hundreds to thousands of years and is therefore not a practical option. But the current study – led by Columbia University, University of Iceland, University of Toulouse and Reykjavik Energy – has demonstrated that it can take as little as two years.

Lead author Dr Juerg Matter, Associate Professor in Geoengineering at the University of Southampton, says: “Our results show that between 95 and 98 per cent of the injected CO2 was mineralised over the period of less than two years, which is amazingly fast.”

Carbonate minerals do not leak out of the ground, thus our newly developed method results in permanent and environmentally friendly storage of CO2 emissions,” adds Dr Matter, who is also a member of the University’s Southampton Marine and Maritime Institute and Adjunct Senior Scientist at Lamont-Doherty Earth Observatory Columbia University. “On the other hand, basalt is one of the most common rock type on Earth, potentially providing one of the largest CO2 storage capacity.

Storing CO2 as carbonate minerals significantly enhances storage security which should improve public acceptance of Carbon Capture and Storage as a climate change mitigation technology,” says Dr Matter. “The overall scale of our study was relatively small. So, the obvious next step for CarbFix is to upscale CO2 storage in basalt. This is currently happening at Reykjavik Energy’s Hellisheidi geothermal power plant, where up to 5,000 tonnes of CO2 per year are captured and stored in a basaltic reservoir.”

Source: http://www.southampton.ac.uk/