title: Rational Design of Porous Conjugated Polymers and Roles of Residual Palladium for Photocatalytic Hydrogen Production.
abstract: Developing highly efficient photocatalyts for water splitting is one of the grand challenges in solar energy conversion. Here, we report the rational design and synthesis of porous conjugated polymer (PCP) that photocatalytically generates hydrogen from water splitting. The design mimics natural photosynthetics systems with conjugated polymer component to harvest photons and the transition metal part to facilitate catalytic activities. A series of PCPs have been synthesized with different light harvesting chromophores and transition metal binding bipyridyl (bpy) sites. The photocatalytic activity of these bpy-containing PCPs can be greatly enhanced due to the improved light absorption, better wettability, local ordering structure, and the improved charge separation process. The PCP made of strong and fully conjugated donor chromophore DBD (M4) shows the highest hydrogen production rate at ∼33 μmol/h. The results indicate that copolymerization between a strong electron donor and weak electron acceptor into the same polymer chain is a useful strategy for developing efficient photocatalysts. This study also reveals that the residual palladium in the PCP networks plays a key role for the catalytic performance. The hydrogen generation activity of PCP photocatalyst can be further enhanced to 164 μmol/h with an apparent quantum yield of 1.8% at 350 nm by loading 2 wt % of extra platinum cocatalyst.
authors.affiliation: Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Lianwei
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Zhengxu
authors.initials: Z
authors.lastname: Cai
authors.affiliation: Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Qinghe
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Wai-Yip
authors.initials: WY
authors.lastname: Lo
authors.affiliation: Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Na
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , 9700 South Cass Avenue, Lemont, Illinois 60439, United States.|Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Lin X
authors.initials: LX
authors.lastname: Chen
authors.affiliation: Department of Chemistry and the James Franck Institute, The University of Chicago , 929 East 57th Street, Chicago, Illinois 60637, United States.
authors.forename: Luping
authors.initials: L
authors.lastname: Yu