Photocatalysis using a Wide Range of the Visible Light Spectrum: Hydrogen Evolution from Doped AgGaS 2

Doping of nickel into AgGaS 2 yields a new absorption band, at a wavelength longer than the intrinsic absorption band of the AgGaS 2 host. The doped nickel forms an electron donor level in a forbidden band of AgGaS 2 . The nickel‐doped AgGaS 2 with rhodium co‐catalyst shows photocatalytic activity for sacrificial H 2 evolution under the light of up to 760 nm due to the transition from the electron donor level consisting of Ni 2+ to the conduction band of AgGaS 2 . Apparent quantum yields for the sacrificial H 2 evolution at 540–620 nm are about 1 %. Moreover, the nickel‐doped AgGa 0.75 In 0.25 S 2 also responds to near‐IR light, up to 900 nm.