This new Catalyst converting Sunlight into Chemical energy efficiently with a Solar cell

We know the basic photosynthesis occurs in nature where sunlight converting the CO2 and H2O into fuels. Scientists have been trying to mimic this process of photosynthesis in a lab from a very long time. Now, a cheap chemical catalyst has carried out part of this process by supplying electricity from a solar cell to split Carbondioxice (CO2) into energy rich Carbonmonoxide (CO) and Oxygen (O2) with a record efficiency. Though this process isn't efficient enough to compete with the fossil fuels like gasoline but scientists are hoping that it could one day lead to methods of making of liquid fuels using Sunlight from CO2, H2O which are the major culprits in global warming.

Saying about it John Turner, a renewable fuels expert from National Renewable Energy Laboratory, Colarado... 

The transformation begins when CO2 is broken down into oxygen and CO, the latter of which can be combined with hydrogen to make a variety of hydrocarbon fuels. Adding four hydrogen atoms, for example, creates methanol, a liquid fuel that can power cars. 

Over the last 2 decades, researchers have discovered a number of catalysts that enable that first step and split CO2 when the gas is bubbled up through water in the presence of an electric current. One of the best studied is a cheap, plentiful mix of copper and oxygen called copper oxide. The trouble is that the catalyst splits more water than it does CO2, making molecular hydrogen (H2), a less energy-rich compound, says Michael Graetzel, a chemist at the Swiss Federal Institute of Technology in Lausanne, whose group has long studied these CO2-splitting catalysts.

Last year, Marcel Schreier, one of Graetzel’s graduate students, was looking into the details of how copper oxide catalysts work. He put a layer of them on a tin oxide–based electrode, which fed electrons to a beaker containing water and dissolved CO2. Instead of splitting mostly water—like the copper oxide catalyst—the new catalyst generated almost pure CO. “It was a discovery made by serendipity,” Graetzel says.

(Coutesy by sciencemag.org)

The tin layer seems to deactivate the catalytic hot spots that helps to split the water molecule. As a result, almost all electric current went into making the more desirable CO. To speedup this process, Graetzel’s team remade their electrode from copper oxide nano wires which have high surface area for carrying out the CO2-breaking reaction, and topped them with a single atom thick layer of tin as the team reports this week in Nature Energy, the strategy worked out. converting 90% of the CO2 molecules into CO, with hydrogen and other byproducts making up the rest. They also hooked their setup to a solar cell and showed that a record 13.4% of the energy in the captured sunlight was converted into the CO’s chemical bonds. That’s far better than plants, which store energy with about 1% efficiency, and even tops recent hybrid approaches that combine catalysts with microbes to generate fuel.

The above experiments indicating that we are in making progress that not only show us a way in generation of greener fuels, but also helps in a way to reduce atmospheric pollution and also could lead to other methods for the generation non-conventional energy resources and also pave a way to solve the problems such as the storage of energy and other climate related problems.