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Influence of Thermal and Photochemical Treatments on Structure and Optical Properties of Single‐Layer Carbon Nitride
Author(s) -
Stroyuk Oleksandr,
Panasiuk Yaroslav,
Raevskaya Alexandra,
Kuchmiy Stepan
Publication year - 2019
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201800279
Subject(s) - carbon nitride , quantum yield , colloid , carbon fibers , photochemistry , exfoliation joint , aqueous solution , nitride , photoluminescence , materials science , chemistry , quenching (fluorescence) , thermal treatment , melamine , graphitic carbon nitride , chemical engineering , photocatalysis , layer (electronics) , organic chemistry , catalysis , nanotechnology , fluorescence , physics , graphene , optoelectronics , quantum mechanics , composite number , composite material , engineering
The temperature of the synthesis of bulk graphitic carbon nitride (GCN) by the polycondensation of melamine, T p , is found to affect the structure and spectral properties of colloidal single layer carbon nitride (SLCN) nanosheets produced from the bulk GCN via the liquid‐phase exfoliation. As T p is elevated the SLCN sheets get decorated with hydroxyl groups and become smaller due to a higher degree of destruction of the original bulk GCN. Both the size decrease and the presence of OH groups in the SLCN contribute to an increase in the photoluminescence (PL) quantum yield growing up to 56% for T p = 700 °C. The illumination of colloidal SLCN in air‐saturated aqueous solutions results in the oxidation of nanosheets with a partial conversion of amino groups into COH groups in reactions with oxygen. The oxidation also results in the fragmentation of SLCN particles into smaller moieties and PL quenching. Oppositely, the illumination in argon‐saturated solutions results in the reduction of SLCN sheets with the formation of CC bonds between the components of adducts of SLCN with the products of a partial polyheptazine hydrolysis as well as between separate SLCN particles accompanied by the elimination of amino and hydroxyl groups.