Interfacially Synthesized 2D COF Thin Film Photocatalyst: Efficient Photocatalyst for Solar Formic Acid Production from CO2 and Fine Chemical Synthesis

The targeted synthesis of an efficient, visible light active, recyclable, freestanding covalent organic framework thin film photocatalyst for multi-facet photocatalysis is the essence of the proposed work. A simple, scalable, reagent free synthesis of a thin film at the interface of 5,10,15,20-tetra-(4-aminophenyl)porphyrin, 2-vinylbenzene-1,4-dicarbaldehyde in nitrobenzene and aqueous glyoxal affords centimetre sized continuous 2D thin films with substantial stability, flexibility and efficient visible light activity. Strikingly different from the regular imine based COF, incorporation of glyoxal units as a modulator helps in band gap tuning and induces flexibility within the thin film. An interplay between time and concentrations helps in achieving a thin film photocatalyst with efficient photocatalytic activity for 1,4-NADH regeneration and selective formic acid formation from CO2. The optimum band edge position of the thin film photocatalyst also enables it with solar fine chemical synthesis via reductive dehalogenation under visible light illumination with excellent recyclability. The present work gives insight into visible light active thin film formation en route to metal-free sustainable photocatalysis.