Fabrication of a novel carbon quantum Dots-Modified 2D heterojunction for highly efficient sunlight photocatalysis

• Published in: Journal of alloys and compounds 2019-10, Vol.806, p.761-773
• Main Authors: Chen, Tao, Yin, Dongguang, Zhang, Xinyu, Zhao, Feifei, Khaing, Kyu Kyu, Deng, Linlin, Huang, Kexian, Li, Luqiu, Liu, Jinliang, Zhang, Yong
• Format: Article
• Language: English
• Subjects: 2D heterojunction; Carbon; Carbon nitride; Carbon quantum dots; Catalytic activity; Charge transfer; Electromagnetic absorption; Environmental protection; Fabrication; g-C3N4/MoS2; Heterojunctions; Holes (electron deficiencies); Hydrogen evolution; Molybdenum disulfide; Photocatalysis; Photocatalysts; Photocatalytic activity; Quantum dots; Reagents; Rhodamine; Sunlight
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.07.215

A novel carbon quantum dots- (CDs) modified 2D heterojunction photocatalyst was successfully fabricated by a facile impregnation and calcination approach. The results of photocatalytic experiments showed that the photocatalyst CDs/g-C3N4/MoS2 exhibited tremendously enhanced photocatalytic activity. The rates for hydrogen evolution and degradation of rhodamine B (RhB) under simulated sunlight irradiation were about 5 and 7 times higher than those of pristine g-C3N4. Moreover, its photocatalytic activity was higher than those of g-C3N4/MoS2, the benchmark reagent P25, and other heterojunctions reported previously. Heterojunctins loaded with different percentages of CDs by weight were synthesized and it was found that the heterojunctin with 2% of CDs showed the highest efficiency. The possible mechanism for enhanced activity was proposed. The great enhancement of photocatalytic activity could be ascribed to the CDs modification and the formation of the 2D heterojunction, which greatly facilitate the charge transfer at interfaces, reduce the recombination rates of photoinduced electron-hole pairs, and increase the light absorption. The results reveal that the construction of CDs-modified 2D heterojunction is a facile strategy to boost the sunlight-driven photocatalytic activity for semiconductor photocatalysts, facilitating their practical applications in environmental protection. [Display omitted] •A novel carbon quantum dots (CDs) modified 2D heterojunction was successfully fabricated.•The product was prepared by a facile impregnation and calcination approach.•The prepared product exhibited tremendously enhanced photocatalytic activity.•The enhanced activity can be ascribed to the CDs modification and formation of 2D heterojunction.