A Superficial Intramolecular Alignment of Carbon Nitride through Conjugated Monomer for Optimized Photocatalytic CO2 Reduction

Abstract

One of the most frequent ways to widen the adsorption range of carbon nitride (CN) is to add a well-known photosensitizer into its basic structure. So far, such attachments have been accomplished by using weak van der Waals forces. However, using strong covalent bonding to attach such photosensitizer with CN is yet to be determined. Here, for the first time, we covalently bonded porphyrin (5,10,15,20-tetrakis(4-(2,4-diamino-1,3,5-triazinyl) phenyl)-Porphyrin (TDP)), a renowned photosensitizer, effectively with CN by thermally balanced molecular strategy. A photoreaction system was set up for the deoxygenated conversion of CO2 to CO under visible light, where cobalt acted as a redox controller to speed up the charge transportation, while CN-TDP worked as a CO2 activating photocatalyst. The subsequent photocatalyst has a broader absorbance range, a greater specific surface area, and intramolecular organic connections that help to decrease the electron-hole pairs’ recombination rate. Furthermore, the average weight ratio between urea and TDP was well-tuned, resulting in a fantastic CO2 photoconversion for CN-TDP7.0 compared to the blank sample. This substantial increase in photocatalytic activity predicts a significant shift in CN’s specific surface area, band gap, chemical composition, and structure, as well as the efficient separation of photogenerated charge carriers from the ground state (HOMO) to the excited state (LUMO), making it a top candidate for CO2 photoreduction. At the same time, this approach paves the path for the bottom-up fabrication of carbon nitride nanosheets.

Nanostructure Engineering via Intramolecular Construction of Carbon Nitride as Efficient Photocatalyst for CO2 Reduction

“…Carbon nitride (CN) has received considerable attention as a metal-free organic semiconductor due to its remarkable thermal and chemical stability and favorable electrical structure [29][30][31][32][33][34][35]. CN has been shown to be a potential solar energy conversion candidate [36,37].…”

Molecular grafting based polymeric carbon nitride for wondrous artificial photosynthesis

“…40,45 Particularly for photochemical hydrogen production, the alteration approaches for adjusting the electronic configuration texture and surface morphology of PCN have already been instituted. [46][47][48][49][50] Numerous strategies have been developed to enhance the photocatalytic behavior of PCN, including element doping 4,20 and heterojunction with other semiconductors.…”

“…Particularly for photochemical hydrogen production, the alteration approaches for adjusting the electronic configuration texture and surface morphology of PCN have already been instituted 46‐50 . Numerous strategies have been developed to enhance the photocatalytic behavior of PCN, including element doping 4,20 and heterojunction with other semiconductors. Molecular Engineering (Copolymerization process) has also been used to optimize luminous absorbance and the performance of charge transmission segregation 4,20 .…”

“…Numerous strategies have been developed to enhance the photocatalytic behavior of PCN, including element doping 4,20 and heterojunction with other semiconductors. Molecular Engineering (Copolymerization process) has also been used to optimize luminous absorbance and the performance of charge transmission segregation 4,20 . Covalently organic polymers have several merits such as being feasible, price efficient, and having a configurable band gap that can be adapted using numerous organic additives.…”

“…The semiconductor-mediated photocatalytic progression of energy generation through water splitting driven by renewable fuel has sparked considerable interest because it holds great promise for photovoltaics in resolving worldwide energy as well as ecosystem complications. [1][2][3][4][5] Since the production of fossils into the surroundings has increased at an extraordinary record-breaking rate due to fuel fission. [6][7][8] To address such ubiquitous regard, various sorts of photovoltaic tools have been investigated for the recycling of solar energy into fuels.…”