Embedding Aromatic Conjugated Monomer within Carbon Nitride for Efficient Photocatalytic Reduction Reactions

• Published in: Journal of Molecular Liquids
• Main Author: Ajmal Z.; Taha T.A.; Amin M.A.; Palamanit A.; Nawawi W.I.; Kalam A.; Al-Sehemi A.G.; Algarni H.; Qadeer A.; Ali H.; Kumar A.; Qian J.; Hayat A.; Zeng H.
• Format: Article
• Language: English
• Published: Elsevier B.V. 2022
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85140488330&doi=10.1016%2fj.molliq.2022.120617&partnerID=40&md5=c9075d231754e402386c824f20b24ef0

Due to a growing number of significant vitality and environmental issues, the standardized variation of carbon nitride (CN) for visible-light photocatalytic water splitting is an encouraging scientific topic. By revealing this, the functionalized monomer 2,6-dibromobenzimidazole (BI) was successfully embedded within the heptazine units of CN via a molecular engineering (Co-polymerization process) approach, and the as-synthesized product was named CN/BIx. Thereafter, as-synthesized materials were employed in the photocatalytic production of hydrogen (H2) via water splitting and CO2 reduction into CO under visible light irradiance (λ = 420 nm). Surprisingly, the substituent framework of CN, which was intimidated by the description of BI monomer, acted as a substitution reaction material and lubricated the electronic structure of CN by endorsing charge transition dissociation, which in turn boosted its photocatalytic performance under visible irradiation. The CN/BI10.0 yields 62.8 mol of CO and 18.1 mol of H2 for 4 h of the catalyzed reaction upon photooxidation under light irradiation, emphasizing the maximum photocatalytic performance with response to CO2+. Correspondingly, the H2 evolution rate (HER) for bulk CN was estimated as 17.6 mol/h1, whereas it was approximated as 203.7 mol/h1 for CN/BI10.0, which is 10 times higher than that of CN. Such a phenomenon also predicts a substantial encroachment in the surface area, energy gap, and chemical properties, along with promotes the effective segregation of photoinduced charge separation from the valence band (VB) to the conduction band (CB) of CN, thereby, making it a good alternative for the photocatalytic water and CO2 reduction reaction process. © 2022 Elsevier B.V.