Pyrene‐ and Bipyridine‐based Covalent Triazine Framework as Versatile Platform for Photocatalytic Solar Fuels Production**

Abstract

The ability to molecularly engineer materials is a powerful tool toward increasingly performing heterogeneous catalysts. Porous organic polymers stand out as photocatalysts due to their high chemical stability, outstanding optoelectronic properties and their easy and tunable syntheses. In photocatalysis, the insertion of photosensitizing π-extended molecules into molecularly well-defined donor-acceptor junctions is supposed to increase the catalytic activity, but yet remain experimentally underdeveloped. This study presents a pyrene-based Covalent Triazine Framework (CTF) synthesized through a polycondensation approach, which was designed to contain a molecularlydefined pyrene-triazine-bipyridine donor-acceptor-acceptor triad as the repetition unit of the CTF. The CTF is an efficient photocatalyst for hydrogen evolution from water reaching a significant production rate of 61.5 mmol H2 /h/g cat . Moreover, the same CTF can easily be used as porous macroligand for an organometallic Rh complex to efficiently catalyze the carbon dioxide photoreduction into formic acid under visible light.

Covalent Organic Frameworks for Photocatalytic Hydrogen Peroxide Generation

“… Covalent triazine frameworks (CTFs), a subclass of COFs, have also attracted a great deal of interest for their potential application in the photocatalytic H 2 O 2 generation.Covalent triazine frameworks (CTFs), a subcategory of COFs, have received attention because of their several benefits, including high nitrogen content, chemical tunability, large surface areas, persistent microporosity, and thermochemical stability. − Mostly, CTFs have been prepared by acid-catalyzed trimerization reaction of aromatic nitriles or condensation reaction of aromatic aldehydes, benzylamine or amides. Owing to the extended conjugated structure in two dimensions and strong visible light absorption, the potential application of covalent triazine frameworks for photocatalytic hydrogen peroxide generation has also been explored.…”

Efficient integration of covalent triazine frameworks (CTFs) for augmented photocatalytic efficacy: A review of synthesis, strategies, and applications

“…This approach not only enables the rational design of CTFs with tailored band structures at the molecular level but also expedites the transfer of electrons from the highest occupied molecular orbital (HOMO) of the electron-donating unit to the lowest unoccupied molecular orbital (LUMO) of the adjacent electron-accepting unit, thereby engendering an internal electric field. Consequently, this facilitates the dissociation of excitons into liberated electrons and holes, while concurrently extending the carrier lifetime, thereby enhancing charge separation and transfer within the CTF [ 41 , 54 , [134] , [135] , [136] , [137] , [138] , [139] , [140] , [141] , [142] , [143] , [144] , [145] , [146] , [147] , [148] , [149] , [150] , [151] , [152] , [153] , [154] , [155] , [156] , [157] , [158] , [159] , [160] , [161] ]. These numerous benefits offer a plethora of opportunities for the synthesis and refinement of CTF derivatives that satisfy a wide range of uses.…”

“…It is preferred that the photocatalyst integrates dual or more functions into a single reaction system while simultaneously taking the environment and energy into account [ 134 , 142 , 153 , 182 , 265 , 267 , [275] , [276] , [277] , [278] ]. The establishment of suitable energy structures is essential to initiate the dual reactive process required for photocatalysis [ 120 , 158 , 182 ].…”

Monitoring structure and coordination chemistry of Co4O4-based oxygen evolution catalysts by nitrogen-14/-15 and cobalt-59 NMR spectroscopy

“…Thus, the higher activity of Co 4 TPT compared Co 4 O 4 (OAc) 4 Py 4 is most likely due to the change of the electron density on the active cubane core. The replacement of a proton (Hammett constant of 0) in the 4-position of the pyridine by a triazine core (Hammett constant of 0.29 29 ) in the framework TPT-linker causes a lower electron density on the pyridine and subsequently on the Co core. For a series of molecular cubanes, Wang et al correlated a lower electron density on the Co core with a higher reaction rate.…”