title: Ga-Promoted Photocatalytic H2 Production over Pt/ZnO Nanostructures.
abstract: Photocatalytic H2 generation is investigated over a series of Ga-modified ZnO photocatalysts that were prepared by hydrothermal methods. It is found that the structural, textural, and optoelectronic properties remarkably depend on the Ga content. The photocatalytic activity is higher in samples with Ga content equal to or lower than 5.4 wt %, which are constituted by Zn1-xGaxO phases. Structural, textural, and optoelectronic characterization, combined with theoretical calculations, reveals the effect of Ga in the doped ZnO structures. Higher Ga incorporation leads to the formation of an additional ZnGa2O4 phase with spinel structure. The presence of such a phase is detrimental for the textural and optoelectronic properties of the photocatalysts, leading to a decrease in H2 production. When Pt is used as the cocatalyst, there is an increase of 1 order of magnitude in the activity with respect to the bare photocatalysts. This is a result of Pt acting as an electron scavenger, decreasing the electron-hole recombination rate and boosting the H2 evolution reaction.
authors.forename: Julio
authors.initials: J
authors.lastname: Núñez
authors.forename: Fernando
authors.initials: F
authors.lastname: Fresno
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors.forename: Ana E
authors.initials: AE
authors.lastname: Platero-Prats
authors.forename: Prabhas
authors.initials: P
authors.lastname: Jana
authors.affiliation: Group of Sustainable Energy and Chemistry (EQS), Institute of Catayisis and Petrochemistry (ICP-CSIC) , c/Marie Curie 2, 28049 Cantoblanco, Madrid, Spain.
authors.forename: José L G
authors.initials: JL
authors.lastname: Fierro
authors.forename: Juan M
authors.initials: JM
authors.lastname: Coronado
authors.affiliation: Chemical and Environmental Engineering Group, ESCET, Rey Juan Carlos University , c/Tulipán s/n, 28933 Móstoles, Madrid, Spain.
authors.forename: David P
authors.initials: DP
authors.lastname: Serrano
authors.forename: Víctor A
authors.initials: VA
authors.lastname: de la Peña O'Shea
keywords: Ga; Pt; ZnO; cocatalyst; doping; photocatalytic H2 production