Modification of g-C3N4 nanosheets by carbon quantum dots for highly efficient photocatalytic generation of hydrogen

• Published in: Applied surface science Vol. 375; pp. 110 - 117
• Main Authors: Li, Kui, Su, Feng-Yun, Zhang, Wei-De
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2016
• Subjects: Carbon; Carbon nitride; Carbon quantum dots; Displays; Graphitic carbon nitride; Hydrogen generation; Light irradiation; Nanostructure; Photocatalysis; Quantum dots; Surface chemistry; Carbon quantum dots; Hydrogen generation; Photocatalysis; Graphitic carbon nitride
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2016.03.025

Carbon quantum dots-modified graphitic carbon nitride nanosheets (CNNS/CQDs) catalysts with high and stable activity for photocatalytic generation of hydrogen through water splitting were successfully constructed. [Display omitted] •Composite photocatalysts based on g-C3N4 nanosheets and CQDs were prepared.•High visible light photocatalytic activity for H2 evolution.•Effective separation and transfer of charge carriers. Carbon quantum dots (CQDs) were deposited onto graphite-like carbon nitride nanosheets (CNNS) to form CNNS/CQDs composites. The prepared CNNS/CQDs composites exhibit much higher photocatalytic activity under visible light irradiation than pure CNNS do. The CNNS/CQDs-7 sample displays the highest photocatalytic performance, with H2 production rate of 116.1μmolh−1, which is three times of that over pure CNNS (37.8μmolh−1). Photoluminescence spectroscopy and photoelectrochemical (PEC) analysis reveal that the CQDs are favorable for trapping electrons and promoting the separation of photogenerated electron-hole pairs in CNNS. A possible photocatalytic mechanism of the enhanced photocatalytic performance for H2 generation over CNNS/CQDs will be proposed in this paper.