title: Nano-sized quaternary CuGa2In3S8 as an efficient photocatalyst for solar hydrogen production.
abstract: The synthesis of quaternary metal sulfide (QMS) nanocrystals is challenging because of the difficulty to control their stoichiometry and phase structure. Herein, quaternary CuGa2In3S8 photocatalysts with a primary particle size of ≈4 nm are synthesized using a facile hot-injection method by fine-tuning the sulfur source injection temperature and aging time. Characterization of the samples reveals that quaternary CuGa2In3S8 nanocrystals exhibit n-type semiconductor characteristics with a transition band gap of ≈1.8 eV. Their flatband potential is located at -0.56 V versus the standard hydrogen electrode at pH 6.0 and is shifted cathodically by 0.75 V in solutions with pH values greater than 12.0. Under optimized conditions, the 1.0 wt % Ru-loaded CuGa2In3S8 photocatalyst exhibits a photocatalytic H2 evolution response up to 700 nm and an apparent quantum efficiency of (6.9±0.5) % at 560 nm. These results indicate clearly that QMS nanocrystals have great potential as nano-photocatalysts for solar H2 production.
authors.affiliation: Division of Physical Sciences and Engineering, KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900 (Saudi Arabia); Department of Chemistry, Faculty of Science, Sohag University, Sohag 82524 (Egypt). kandiel@science.sohag.edu.eg.
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Kandiel
authors.forename: Dalaver H
authors.initials: DH
authors.lastname: Anjum
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takanabe
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry* / Q000528:radiation effects; D005708:Gallium / Q000737:chemistry* / Q000528:radiation effects; D006859:Hydrogen / Q000737:chemistry*; D007204:Indium / Q000737:chemistry* / Q000528:radiation effects; D053758:Nanoparticles / Q000737:chemistry* / Q000528:radiation effects; D055668:Photochemical Processes; D013440:Sulfides / Q000737:chemistry* / Q000528:radiation effects; D013472:Sunlight
chemical_list: D013440:Sulfides; D007204:Indium; D003300:Copper; D006859:Hydrogen; D005708:Gallium
keywords: copper; gallium; hydrogen; indium; photochemistry