Sol−Gel Processing of Water‐Soluble Carbon Nitride Enables High‐Performance Photoanodes. Issue 10 (3rd March 2021)

• Record Type: Journal Article
• Authors: Adler, Christiane; Krivtsov, Igor; Mitoraj, Dariusz; dos Santos‐Gómez, Lucía; García‐Granda, Santiago; Neumann, Christof; Kund, Julian; Kranz, Christine; Mizaikoff, Boris; Turchanin, Andrey; Beranek, Radim
• Is Part Of: ChemSusChem. Volume 14:Issue 10(2021)
• Page Start: 2170
• Page End: 2179
• Publication Date: 2021-03-03
• Subjects: bias-free operation -- carbon nitride -- photoanode -- photoelectrocatalysis -- photoreforming; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.202100313
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: 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 −2 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. Abstract : Completely unbiased : Robust binder‐free films derived from sol−gel processing of a water‐soluble polymeric carbon nitride precursor exhibit unprecedented performance in photoelectrocatalytic reforming of alcohols, including effective operation under bias‐free conditions.