Title: Photocathode Chromophore–Catalyst Assembly via Layer-By-Layer Deposition of a Low Band-Gap Isoindigo Conjugated Polyelectrolyte

Abstract

Low band-gap conjugated polyelectrolytes (CPEs) can serve as efficient chromophores for use on photoelectrodes for dye-sensitized photoelectrochemical cells. Herein is reported a novel CPE based on poly(isoindigo-co-thiophene) with pendant sodium butylsulfonate groups (PiIT) and its use in construction of layer-by-layer (LbL) chromophore–catalyst assemblies with a Pt-based H+ reduction catalyst (PAA-Pt) for water reduction. A novel Stille polymerization/postpolymerization ion-exchange strategy was used to convert an organic-soluble CPE to the water-soluble poly(isoindigo-co-thiophene). The anionic PiIT polyelectrolyte- and polyacrylate-stabilized Pt-nanoparticles (PAA-Pt) were codeposited with cationic poly(diallyldimethylammonium) chloride (PDDA) onto inverse opal (IO), nanostructured indium tin oxide film (nITO) (IO nITO) atop fluorine doped tin oxide (FTO), by using LbL self-assembly. To evaluate the performance of novel conjugated PiIT//PAA-Pt chromphore–catalyst assemblies, interassembly hole transfer was investigated by photocurrent density measurements on FTO//IO nITO electrodes. Enhanced cathodic photocurrent is observed for the polychromophore–catalyst assemblies, compared to electrodes modified with only PiIT, pointing toward photoinduced hole transfer from the excited PilT to the IO nITO. Prolonged photoelectrolysis experiments reveal H2 production with a Faradaic yield of approximately 45%. This work provides new routes to carry out visible-light-driven water reduction using photocathode assemblies based on low band-gap CPEs.

Authors:

Leem, Gyu  ^[1];

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• Search DOE PAGES for ORCID "0000-0003-0169-1096"

Black, Hayden T. ^[2]; Shan, Bing ^[3]; Bantang, Jose P. O. ^[4]; Meyer, Thomas J.  ^[3];

• Search DOE PAGES for author "Meyer, Thomas J."
• Search DOE PAGES for ORCID "0000-0002-7006-2608"

Reynolds, John R.  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-7417-4869"

Schanze, Kirk S.  ^[1]

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• Search DOE PAGES for ORCID "0000-0003-3342-4080"

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1. Univ. of Texas at San Antonio, TX (United States). Dept. of Chemistry
2. Georgia Inst. of Technology, Atlanta, GA (United States). School of Chemistry and Biochemistry, School of Materials Science and Engineering, Center for Organic Photonics, and Electronics, Georgia Tech Polymer Network
3. Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Chemistry
4. Univ. of Texas at San Antonio, TX (United States). Dept. of Chemistry; De La Salle Univ., Manila (Philippines). Dept. of Chemistry

Publication Date:

Wed Jan 03 00:00:00 EST 2018

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for Solar Fuels (UNC EFRC)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1470088

Grant/Contract Number:  

SC0001011

Resource Type:

Accepted Manuscript

Journal Name:

ACS Applied Energy Materials

Additional Journal Information:

Journal Volume: 1; Journal Issue: 1; Related Information: UNC partners with University of North Carolina (lead); Duke University; University of Florida; Georgia Institute of Technology; University; North Carolina Central University; Research Triangle Institute; Journal ID: ISSN 2574-0962

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 08 HYDROGEN; catalysis (homogeneous); catalysis (heterogeneous); solar (photovoltaic); solar (fuels); photosynthesis (natural and artificial); hydrogen and fuel cells; electrodes - solar; charge transport; materials and chemistry by design; synthesis (novel materials); synthesis (self-assembly)