title: Direct Observation of Photoinduced Charge Separation in Ruthenium Complex/Ni(OH)2 Nanoparticle Hybrid.
abstract: Ni(OH)2 have emerged as important functional materials for solar fuel conversion because of their potential as cost-effective bifunctional catalysts for both hydrogen and oxygen evolution reactions. However, their roles as photocatalysts in the photoinduced charge separation (CS) reactions remain unexplored. In this paper, we investigate the CS dynamics of a newly designed hybrid catalyst by integrating a Ru complex with Ni(OH)2 nanoparticles (NPs). Using time resolved X-ray absorption spectroscopy (XTA), we directly observed the formation of the reduced Ni metal site (~60 ps), unambiguously demonstrating CS process in the hybrid through ultrafast electron transfer from Ru complex to Ni(OH)2 NPs. Compared to the ultrafast CS process, the charge recombination in the hybrid is ultraslow (≫50 ns). These results not only suggest the possibility of developing Ni(OH)2 as solar fuel catalysts, but also represent the first time direct observation of efficient CS in a hybrid catalyst using XTA.
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, Wisconsin, 53201.
authors.forename: Yu
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, Wisconsin, 53201.
authors.forename: Brian
authors.initials: B
authors.lastname: Pattengale
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, Wisconsin, 53201.
authors.forename: John
authors.initials: J
authors.lastname: Ludwig
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, Wisconsin, 53201.
authors.forename: Abderrahman
authors.initials: A
authors.lastname: Atifi
authors.affiliation: Material Science Division, Argonne National Laboratory, Argonne, Illinois, 60349.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Zinovev
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, Wisconsin, 53201.
authors.forename: Bin
authors.initials: B
authors.lastname: Dong
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois, 60349.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Kong
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois, 60349.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zuo
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois, 60349.
authors.forename: Xiaoyi
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Marquette University, Milwaukee, Wisconsin, 53201.
authors.forename: Jier
authors.initials: J
authors.lastname: Huang