Nitrogen-doped carbon nanotubes are selective and robust electrocatalysts for CO2 reduction to formate in aqueous media without the use of a metal catalyst. Polyethylenimine (PEI) functions as a co-catalyst by significantly reducing catalytic overpotential and increasing current density and efficiency. The co-catalysis appears to help in stabilizing the singly reduced intermediate CO2(•-) and concentrating CO2 in the PEI overlayer.

The dye-sensitized photoelectrosynthesis cell (DSPEC) integrates high bandgap, nanoparticle oxide semiconductors with the light-absorbing and catalytic properties of designed chromophore-catalyst assemblies. The goals are photoelectrochemical water splitting into hydrogen and oxygen and reduction of CO by water to give oxygen and carbon-based fuels. Solar-driven water oxidation occurs at a photoanode and water or CO reduction at a cathode or photocathode initiated by molecular-level light absorption. Light absorption is followed by electron or hole injection, catalyst activation, and catalytic water oxidation or water/CO reduction. The DSPEC is of recent origin but significant progress has been made. It has the potential to play an important role in our energy future.

photoelectrochemical cell | photosytem II | water splitting | solar fuels | artificial photosynthesis

Widespread implementation of renewable energy technologies, while preventing significant increases in greenhouse gas emissions, appears to be the only viable solution to meeting the wor d"s energy dem nds for sust in b e energy future. The fin energy mix wi inc ude conservation and energy efficiency, wind, geothermal, biomass, and others, but none more ubiquitous or abundant than the sun. Over several decades of development, the cost of photovoltaic cells has decreased significantly with lifetimes that exceed 25 years and there is promise for widespread implementation in the future. However, the solar input is intermittent and, to be practical at a truly large scale, will require an equally large capability for energy storage. One approach involves artificial photosynthesis and the use of the sun to drive solar fuel reactions for water splitting into hydrogen and oxygen or to reduce CO 2 to reduced carbon fuels. An early breakthrough in this area came from an initial report by Honda and Fujishima on photoelectrochemical water splitting at TiO 2 with UV excitation. Significant progress has been made since in exploiting semiconductor devices in water splitting with impressive gains in spectral coverage and solar efficiencies. An alternate, hybrid approach, which integrates molecular light absorption and catalysis with the band gap properties of oxide semiconductors, the dye-sensitized photoelectrosynthesis cell (DSPEC), has been pioneered by the University of North Carolina Energy Frontier Research Center (UNC EFRC) on Solar Fuels. By utilizing chromophore-catalyst assemblies, core/shell oxide structures, and surface stabilization, the EFRC recently demonstrated a viable DSPEC for solar water splitting.

Conjugated linoleic acid (CLA) is a unique lipid that elicits dramatic reductions in adiposity in several animal models when included at < or = 1% of the diet. Despite a flurry of investigations, the precise mechanisms by which conjugated linoleic acid elicits its dramatic effects in adipose tissue and liver are still largely unknown. In vivo and in vitro analyses of physiological modifications imparted by conjugated linoleic acid on protein and gene expression suggest that conjugated linoleic acid exerts its de-lipidating effects by modulating energy expenditure, apoptosis, fatty acid oxidation, lipolysis, stromal vascular cell differentiation and lipogenesis. The purpose of this review shall be to examine the recent advances and insights into conjugated linoleic acid's effects on obesity and lipid metabolism, specifically focused on changes in gene expression and physiology of liver and adipose tissue.