Researchers from the University of Antwerp and KU Leuven have devised an all-gas-phase photo-electrochemical cell (PEC) that produces hydrogen gas from contaminated gas.
The PEC system works most efficiently with organic pollutants in inert carrier gas. The cell performs less efficiently in the presence of oxygen gas, but still generates significant photocurrents, showing the cell can be run on organic contaminated air. The study, presented in the journal ChemSusChem, suggests a possible pathway toward photo-electrochemical remediation of air pollution with simultaneous energy recovery.
Today’s society is faced with two persistent demands: sustainable energy production and a healthy living environment. In both contexts, the use of semiconductors for photocatalysis has been identified as an important technology. Heterogeneous photocatalysis has proven to be successful in both light-driven hydrogen production through water splitting, as well as for the degradation of organic pollutants in gaseous media.
In this study both applications are coupled in a single device; a solid and stand-alone photo-electrochemical (PEC) cell. In doing so part of the energy stored in airborne organic pollutants is recovered by hydrogen production, while mineralizing the contaminants to less harmful CO2. Oxidation of volatile organic compounds (VOC) occurs at the photo-anode, while hydrogen is produced at the (dark) cathode on the opposite side of a proton-conducting solid electrolyte membrane. It is worth mentioning that also aqueous waste streams can be treated using PEC cells.—Verbruggen et al.
|Schematic representation of the photo-electrochemical cell. Verbruggen et al. Click to enlarge.|
Sammy W. Verbruggen, Myrthe Van Hal, Tom Bosserez, Jan Rongé, Birger Hauchecorne, Johan A. Martens and Silvia Lenaerts (2017) “Harvesting Hydrogen Gas from Air Pollutants with an Unbiased Gas Phase Photoelectrochemical Cell” ChemSusChem doi: 10.1002/cssc.201601806