Synthesis and testing of carbon quantum dots loaded 2D Bi2MoO6 for efficient Hg0 photocatalytic removal

• Published in: Applied surface science Vol. 633; p. 157587
• Main Authors: Zhang, Yili, Zhang, Hanlin, Shu, Yixiang, Zhao, Yongchun, Wang, Xuebin, Xiao, Rihong, Zhang, Junying
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2023
• Subjects: 2D Bi2MoO6/CQDs; Hg0 removal; Photocatalysis; UPCL; Hg0 removal; 2D Bi2MoO6/CQDs; UPCL; Photocatalysis
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2023.157587

•A 2D Bi2MoO6/CQDs photocatalyst was prepared by hydrothermal method.•2D Bi2MoO6/CQDs showed good visible and near-infrared light Hg0 removal performance.•The introduction of CQDs reduced the carrier recombination rate of 2D Bi2MoO6.•2D Bi2MoO6/CQDs owned UPCL characteristics. Carbon quantum dots (CQDs) was prepared and supported on 2D Bi2MoO6 by hydrothermal method to prepare 2D Bi2MoO6/CQDs composite photocatalyst with up-conversion luminescence (UPCL) characteristics. The properties of 2D Bi2MoO6/CQDs were characterized by a series of characterization tools. Then, 2D Bi2MoO6 and 2D Bi2MoO6/CQDs catalysts were applied to photocatalytic Hg0 removal. The experimental results show that Hg0 removal efficiency of 2D Bi2MoO6/CQDs increased from 30.5% to 80.1% under visible light and from 7.2% to 26.4% under near-infrared light compared with 2D Bi2MoO6. The photostability test shows that 2D Bi2MoO6/CQDs nanocomposites could maintain high photostability after five photoreaction cycles. UPCL test proved that CQDs had the ability to absorb infrared light and emit visible light, thus expanding the light utilization range of composite catalyst. Moreover, in N2+6%O2+12%CO2+NO atmosphere, Hg0 removal efficiency of 2D Bi2MoO6/CQDs first dropped and then raised with the increase of NO concentration due to the simultaneous reduction and oxidation of NO in the system. Finally, the ESR test shows that the modification of CQDs could not only enhance light absorption rang of photocatalyst, but also promote the transfer of photogenerated carriers on the catalyst surface, thereby enhancing the photocatalytic Hg0 removal capability of the 2D Bi2MoO6/CQDs catalyst.