Traditional silver chloride photocatalytic properties are restricted to ultraviolet and blue light wavelengths. But Yugang Sun, U.S. Department of Energy’s (DOE) Argonne National Laboratory, Illinois, USA, has created visible-light catalysts, using silver chloride nanowires decorated with gold nanoparticles.

Sun started with traditional silver nanowires that were oxidized with iron chloride to create silver chloride nanowires. A sequential reaction with sodium tetrachloroaurate deposited the gold nanoparticles on the wires.

The move into the visible spectrum means that organic molecules in water may be destroyed with visible irradiation from conventional fluorescent light bulbs or the sun, if passed through a film of nanowires of this type. This was demonstrated by the photocatalytic decomposition of an aqueous solution of methylene blue.

• Conversion of Ag Nanowires to AgCl Nanowires Decorated with Au Nanoparticles and Their Photocatalytic Activity
  Y. Sun,
  J. Phys. Chem. C, 2010, 114 (5), 2127–2133.
  DOI: 10.1021/jp9115645