Energy Focus

  • PDF / 185,856 Bytes
  • 1 Pages / 585 x 783 pts Page_size
  • 15 Downloads / 232 Views

DOWNLOAD

REPORT


Energy Quarterly

ENERGY FOCUS Correction of cyanobacteria misinformation could improve biofuels production

Alane stores hydrogen at high capacity http://srnl.doe.gov

Science DOI: 10.1126/science.1210858

The discovery of two enzymes in cyanobacteria that do the work of one missing enzyme has opened new possibilities for genetically engineering bacteria to produce biofuels more efficiently than currently available methods. As reported by Donald Bryant and Shuyi Zhang of The Pennsylvania State University in a recent issue of Science, research done in 1966 concluded that a missing enzyme in cyanobacteria prevented the completion of the tricarboxylic acid (TCA, or Krebs) cycle, which helps to break down biomass through oxidation. This ostensibly rendered the organisms incapable of oxidizing metabolites for energy production. By taking a look 44 years later using modern instrumentation and enhanced biochemical and genetics tools, Bryant and his team discovered two enzymes that perform the same task of the missing enzyme, completing the TCA cycle by a slightly different path. Equipped with this new understanding of how cyanobacteria make energy, the next step for the researchers is to determine how to genetically engineer a cyanobacterial strain to synthesize 1,3-butanediol— an organic precursor for making biofuels.

Quantum dot paint acts as a solar cell ACS Nano DOI: 10.1021/nn20438lg

Researchers at the University of Notre Dame in Indiana, led by Prashant V. Kamat, have developed what they call “SunBelievable” solar paint, using TiO2 nanoparticles coated with CdS and CdSe quantum dots as the solar energy absorbing constituents. Using a pseudo-SILAR (sequential ionic layer absorption and reaction) approach, they deposited Cd2+ along with S2– or Se2– onto suspended TiO2 nanoparticles. Mixing these particles with a tert-butyl alcohol/water solution produced a yellow paint that could be applied in a one-step, brushon process to conducting glass electrodes to form photoanodes. Subsequent photoelectrochemical characterization revealed a rapid photoresponse in each paint type, with photocurrent generation efficiencies of 30–40%. A paint This paste of cadmium sulfide-coated mixture containing both CdS/TiO2 titanium dioxide nanoparticles could turn large surfaces into solar cells. and CdSe/TiO2 yielded the best Credit: ACS Nano. power conversion efficiency of 1%. Although admitting this figure is very low, Kamat said the low cost and the ease of making the solar paint in large quantities could make it a viable solar energy technology if the efficiency can be increased by a moderate amount in the future.

206

Tim Palucka

MRS BULLETIN



VOLUME 37 • MARCH 2012



www.mrs.org/bulletin • Energy Quarterly

With the goal of producing a portable power system small and lightweight enough for soldiers to carry in their backpacks or to power a lightweight drone aircraft, scientists Ted Motyka, Ragaiy Zidan, A system incorporating a fuel cell and light-weight hydrogen storage material. Credit: Savannah River and Kit Heung at the U.S.