Sol-Gel Processing of Water-Soluble Carbon Nitride Enables High-Performance Photoanodes*.
Christiane Adler, Igor Krivtsov, Dariusz Mitoraj, Lucía Dos Santos-Gómez, Santiago García-Granda, Christof Neumann, Julian Kund, Christine Kranz, Boris Mizaikoff, Andrey Turchanin, Radim Beranek
Author Information
Christiane Adler: Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081, Ulm, Germany. ORCID
Igor Krivtsov: Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081, Ulm, Germany. ORCID
Dariusz Mitoraj: Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081, Ulm, Germany. ORCID
Lucía Dos Santos-Gómez: Department of Physical and Analytical Chemistry, University of Oviedo-CINN, 33006, Oviedo, Spain. ORCID
Santiago García-Granda: Department of Physical and Analytical Chemistry, University of Oviedo-CINN, 33006, Oviedo, Spain. ORCID
Christof Neumann: Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Lessingstr. 10, 07743, Jena, Germany. ORCID
Julian Kund: Institute of Analytical and Bioanalytical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
Christine Kranz: Institute of Analytical and Bioanalytical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany. ORCID
Boris Mizaikoff: Institute of Analytical and Bioanalytical Chemistry, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany. ORCID
Andrey Turchanin: Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Lessingstr. 10, 07743, Jena, Germany. ORCID
Radim Beranek: Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081, Ulm, Germany. ORCID
In spite of the enormous promise that polymeric carbon nitride (PCN) materials hold for various applications, the fabrication of high-quality, binder-free PCN films and electrodes has been a largely elusive goal to date. Here, we tackle this challenge by devising, for the first time, a water-based sol-gel approach that enables facile preparation of thin films based on poly(heptazine imide) (PHI), a polymer belonging to the PCN family. The sol-gel process capitalizes on the use of a water-soluble PHI precursor that allows formation of a non-covalent hydrogel. The hydrogel can be deposited on conductive substrates, resulting in formation of mechanically stable polymeric thin layers. The resulting photoanodes exhibit unprecedented photoelectrochemical (PEC) performance in alcohol reforming and highly selective (∼100 %) conversions with very high photocurrents (>0.25 mA cm under 2 sun) down to <0 V vs. RHE. This enables even effective PEC operation under zero-bias conditions and represents the very first example of a 'soft matter'-based PEC system capable of bias-free photoreforming. The robust binder-free films derived from sol-gel processing of water-soluble PCN thus constitute a new paradigm for high-performance 'soft matter' photoelectrocatalytic systems and pave the way for further applications in which high-quality PCN films are required.
