Novel Three-Dimensional Semiconducting Materials Based on Hybrid d¹⁰ Transition Metal Halogenides as Visible Light-Driven Photocatalysts

Abstract

The development of new visible light-driven photocatalysts based on semiconducting materials remains a greatly interesting and challenging task for the purpose of solving the energy crisis and environmental issues. By using photosensitive [(Me) 2 -2,2′-bipy] 2+ (1,1′-dimethyl-2,2′-bipyridinium) cation as template, we synthesized one new type of inorganic−organic hybrid cuprous and silver halogenides of [(Me) 2 -2,2′-bipy]M 8 X 10 (M = Cu, Ag, X = Br, I). The compounds feature a three-dimensional anionic [M 8 X 10 ] 2– network composed of a one-dimensional [M 8 X 12 ] chain based on MX 4 tetrahedral units. The photosensitization of organic cationic templates results in narrow band gaps of hybrid compounds (1.66–2.06 eV), which feature stable visible light-driven photodegradation activities for organic pollutants. A detailed study of the photocatalytic mechanism, including the photoelectric response, photoluminescence spectra, and theoretical calculations, shows that the organic cationic template effectively inhibits the recombination of photoinduced electron–hole pairs leading to excellent photocatalytic activities and photochemical stabilities.