title: Reliable Performance Characterization of Mediated Photocatalytic Water-Splitting Half Reactions.
abstract: Photocatalytic approaches using two sets of semiconductor particles and a pair of redox-shuttle mediators are considered as a safe and economic solution for solar water splitting. Here, accurate experimental characterization techniques for photocatalytic half reactions are reported, investigating the gas as well as the liquid products. The methods are exemplified utilizing photocatalytic titania particles in an iron-based aqueous electrolyte for effective oxygen evolution and mediator reduction reactions under illumination. Several product characterization methods, including an optical oxygen sensor, pressure sensor, gas chromatography, and UV/Vis spectroscopy are used and compared for accurate, high-resolution gas-products and mediator conversion measurements. Advantages of each technique are discussed. A high Faraday efficiency of 97.5±2 % is calculated and the reaction rate limits are investigated.
authors.affiliation: Laboratory of Renewable Energy Science and Engineering, Swiss Federal Institute of Technology in Lausanne (EPFL), Station 9, EPFL, 1015, Lausanne, Switzerland.|Current affiliation: Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California, 91125, United States.
authors.forename: Lihao
authors.initials: L
authors.lastname: Han
authors.affiliation: Laboratory of Renewable Energy Science and Engineering, Swiss Federal Institute of Technology in Lausanne (EPFL), Station 9, EPFL, 1015, Lausanne, Switzerland.
authors.forename: Meng
authors.initials: M
authors.lastname: Lin
authors.affiliation: Laboratory of Renewable Energy Science and Engineering, Swiss Federal Institute of Technology in Lausanne (EPFL), Station 9, EPFL, 1015, Lausanne, Switzerland.
authors.forename: Sophia
authors.initials: S
authors.lastname: Haussener
mesh_terms: D002384:Catalysis; D002849:Chromatography, Gas; D010100:Oxygen / Q000032:analysis; D055668:Photochemical Processes; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D010100:Oxygen
keywords: characterization; mediator; photocatalysis; titania; water splitting