title: Controlling the Photocorrosion of Zinc Sulfide Nanoparticles in Water by Doping with Chloride and Cobalt Ions.
abstract: Photodegradation under UV light irradiation is a major drawback in photocatalytic applications of sulfide semiconductors. ZnS nanoparticles were doped with very low amounts of chloride or cobalt ions in the ppm range and codoped with chloride and cobalt ions during their synthesis by precipitation in aqueous solution followed by calcination. The high-temperature wurtzite phase annealed at 800 °C had a high susceptibility to UV irradiation in water, while the low-temperature zincblende phase annealed at 400 °C was found to be stable. Chlorine doping increased the rate of photocorrosion in water, whereas cobalt doping led to a stabilization of the ZnS nanoparticles. Based on photochemical and spectroscopic investigations applying UV/vis, X-ray photoelectron, and photoluminescence spectroscopy, the increased susceptibility of Cl-doped ZnS is ascribed to a higher number of surface point defects, whereas the stabilization by Co2+is caused by additional recombination pathways for the charge carriers in the bulk, thus avoiding photocorrosion processes at the surface. Additional doping of Cl-doped ZnS with cobalt ions was found to counteract the detrimental effect of the chloride ions efficiently.
authors.affiliation: Laboratory of Industrial Chemistry, Ruhr-University Bochum , 44780 Bochum, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Weide
authors.affiliation: Laboratory of Industrial Chemistry, Ruhr-University Bochum , 44780 Bochum, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Schulz
authors.affiliation: Laboratory of Industrial Chemistry, Ruhr-University Bochum , 44780 Bochum, Germany.|Fraunhofer UMSICHT, 46047 Oberhausen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Kaluza
authors.affiliation: Huntsman Pigments and Additives, Dr. Rudolf-Sachtleben Str. 4, 47198 Duisburg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Rohe
authors.affiliation: Institute of Electrochemistry, Ulm University , Albert-Einstein-Allee 47, 89069 Ulm, Germany.
authors.forename: Radim
authors.initials: R
authors.lastname: Beranek
authors.affiliation: Laboratory of Industrial Chemistry, Ruhr-University Bochum , 44780 Bochum, Germany.|Max Planck Institute for Chemical EnergyConversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Muhler