Synthesis of Layered Carbonitrides from Biotic Molecules for Photoredox Transformations

Abstract

The construction of layered covalent carbon nitride polymers based on tri‐s‐triazine units has been achieved by using nucleobases (adenine, guanine, cytosine, thymine and uracil) and urea to establish a two‐dimensional semiconducting structure that allows band‐gap engineering applications. This biomolecule‐derived binary carbon nitride polymer enables the generation of energized charge carrier with light‐irradiation to induce photoredox reactions for stable hydrogen production and heterogeneous organosynthesis of C−O, C−C, C−N and N−N bonds, which may enrich discussion on chemical reactions in prebiotic conditions by taking account of the photoredox function of conjugated carbonitride semiconductors that have long been considered to be stable HCN‐derived organic macromolecules in space.

Insight into the Enhanced Hydrogen Evolution Activity of 2,4-Diaminopyrimidine-Doped Graphitic Carbon Nitride Photocatalysts

“…Recently, various strategies have been explored to improve the photocatalytic activity of GCN. These strategies can be divided into four categories: (1) combining with carbonaceous nanomaterials, such as graphene, , carbon nanodots, and carbon nanotubes; (2) constructing specific nanostructures; − (3) preparing heterojunction or homojunction − and Z-scheme photocatalysts based on GCN; and (4) elemental − or molecular doping. − For GCN, molecular doping is a unique and effective way that can adjust its structures and properties by introducing organic molecules into its framework. , By now, besides some nonaromatic compounds, − the organics employed to dope GCN are usually benzene-based molecules, ,, thiophene-based molecules, ,, and pyridine-based molecules. ,,, Because pyrimidine rings have strong electron-attracting and electron-capturing abilities owing to high electronegativity of aromatic CC bonds, pyrimidine-based molecules have been introduced into the framework of GCN. ,− The obtained doped GCN samples have been revealed to possess expanded visible light response region and altered electron delocalization and arrangement and thus exhibit enhanced photocatalytic activity, suggesting that pyrimidine-based molecules are excellent dopants for GCN. However, it should be noticed that all of the research studies on molecular doping of GCN have been found to play a positive role in improving light harvesting as well as charge separation and transport of GCN.…”

A Mesoporous Rod-like g-C3N5 Synthesized by Salt-Guided Strategy: As a Superior Photocatalyst for Degradation of Organic Pollutant

“…These unique features help to improve their photocatalytic performance. , Nevertheless, the band gaps of these materials can be greatly influenced by their special structure and N content. , Therefore, CN with special structure has been developed by researchers. − The obtained CN exhibits high surface area and some active sites existing on the surface of the CN materials. , However, these CN materials with special structure still suffer from high band gaps, which result in weak photocatalytic performance and limit their application in photocatalysis. , Thus, there is an inherent driving force to narrow the band gap of CN materials. To enhance photocatalytic performance of CN materials, these materials recently have been fabricated by using different N-rich precursors like melamine, thiourea, and urea. , However, the C/N ratio of CN materials is hardly lower than 0.75. − Therefore, it is significantly important to explore N-rich CN materials with special structure and small band gap to enhance their photocatalytic performance.…”

Heterogeneous Photocatalyzed C−C Cross‐coupling Reactions Under Visible‐light and Near‐infrared Light Irradiation

“…In recent years, Pd supported photocatalysts have been widely reported for photocatalyzed C−C cross‐coupling reactions under visible light irradiation. The solid supports involve visible light responding semiconductors (e. g. WS 2 and Ag/AgBr) and polymers (polydopamine, conjugated microporous poly (benzoxadiazole) and graphitic carbon nitride),,,,,, wide band gap semiconductors (TiO 2 and ZrO 2 , etc. ),,, metal‐organic frameworks (MOF such as NH 2 ‐Uio‐66), magnetic materials (NiFe 2 O 4 ), carbon materials (carbon nanocoil and graphene oxide),, and silica .…”

“…Therefore, g‐C 3 N 4 based photocatalysts are attractive candidates to catalyze Suzuki C−C cross‐coupling reaction. Wang et al . have constructed Pd nanoparticles supported biomolecule‐derived binary carbon nitride polymer g‐CN semiconductor (3 wt.% Pd) and evaluated its photocatalytic activity for Suzuki‐Miyaura cross‐coupling reaction under visible light irradiation at 30 °C.…”