Biomimetic donor-acceptor motifs in carbon nitrides: Enhancing red-light photocatalytic selective oxidation by rational surface engineering

• Published in: Applied catalysis. B, Environmental Vol. 294; p. 120259
• Main Authors: Wang, Chong, Hou, Yuchen, Cheng, Jiajia, Lin, Mei-Jin, Wang, Xinchen
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.10.2021; Elsevier BV
• Subjects: Absorption; Alcohols; Biomimetics; Carbon; Carbon nitride; Catalysts; Catalytic converters; Conjugation; Current carriers; Donor-acceptor; Driving ability; Irradiation; Light; Light irradiation; Nanoparticles; Organic synthesis; Oxidation; Oxidization; Oxygen; Photocatalysis; Photocatalysts; Photochemicals; Photosynthesis; Selectivity; Separation; Surface chemistry; Sustainable production; Transition metals; Wavelength; Donor-acceptor; Organic synthesis; Oxidization; Photocatalysis; Carbon nitride
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2021.120259

[Display omitted] o•Surface engineering photochemical modification is used to fabricate a donor-acceptor (D-A) functional carbon nitride (ECN) photocatalyst•The extension of π-conjugated system and introduction of d-A structure endow the samples better light harvesting and charge transfer capability•The ECN-2 sample exhibits remarkable enhancement in the photocatalytic selective oxidation of alcohols even under 620 nm red-light irradiation.•The photocatalytic aerobic sulfide and sp3 C–H oxidation reactions are also considerably accelerated over ECN photocatalysts Oxidation, especially selective oxidation by a heterogeneous catalyst with molecular oxygen, is a core technology for the conversion of petrochemical feedstock to commodity chemicals and pharmaceuticals. Existing catalytic approaches for efficient aerobic oxidation normally rely on the engagement of organometallic centers or transition-metal nanoparticles. In light of the necessity to develop sustainable production methodologies, multiple approaches for the metal-free polymeric carbon nitride (PCN) photocatalytic selective oxidation have been evaluated. However, the insufficient visible light optical absorption, poor charge-carriers separation and the weak driving force towards oxidation reaction impart a serious restriction on the efficiency and selectivity of the organic photosynthesis, especially under extended wavelength solar light irradiation. Here, we report a surface engineering photochemical modification method to fabricate a donor-acceptor (D-A) functional carbon nitride photocatalyst (ECN) under ambient conditions. The well-developed d-A structure, preserved high crystallinity and enlarged π-conjugation framework of the hybrid semiconductor-molecule ECN samples favor the improvement of the optical absorption, as well as the enhanced separation and migration of the photo-generated charge carriers. As a result, the obtained ECN photocatalysts exhibited remarkable enhancement in the photocatalytic aerobic oxidation of alcohols, even under an extended light wavelength of 620 nm red-light irradiation. The photocatalytic aerobic sulfides and sp3 C–H oxidation reactions were also considerably accelerated over ECN and may serve as a direct approach for the construction of value-added sulfoxide and ketone products.