Highly efficient As(III) removal through simultaneous oxidation and adsorption by N-CQDs modified MIL-53(Fe)

• Published in: Separation and purification technology 2022-04, Vol.286, p.120409, Article 120409
• Main Authors: Chen, Haoyun, Yuan, Xingzhong, Jiang, Longbo, Wang, Hou, Zeng, Guanjun
• Format: Article
• Language: English
• Subjects: AS(III) removal; MIL-53(Fe); Nitrogen doped carbon quantum dots; Photocatalytic oxidation
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2021.120409

The oil vine-like structural of MIL-53(Fe) decorated by N-CQDs exhibits brilliant abilities of As(III) removal efficiency which is achieved through photocatalytic oxidating the As(III) and simultaneous adsorbing the generated arsenate [As(V)]. In situ embed N-CQDs into MIL-53(Fe) was proved to lead an increased charge transportation and improved utilization of the electrons and holes and the edge structure of N-CQDs3/MIL-53(Fe) manifested the significantly As(III) removal ability. [Display omitted] •A promising bifunctional photocatalyst/adsorbent with oil vine like structural of MIL-53(Fe) decorated by N-CQDs was prepared for the first time.•The composite material of MIL-53(Fe) with in situ embedded N-CQDs exhibited brilliant abilities of As(III) oxidation and removal efficiency.•In situ embedding N-CQDs into MIL-53(Fe) was proved to lead an increased charge transportation and improved utilization of the electrons and holes.•The edge structure of N-CQDs3/MIL-53(Fe) manifested the significantly As(III) removal ability. It has been ever attracting increasingly growing demand to develop highly efficient method of aqueous arsenites [As(III)] removal due to the high toxicity of arsenic in drinking water. This work presents an oil vine-like structural MIL-53(Fe) modified by nitrogen doped carbon quantum dots (N-CQDs) with excellent As(III) removal property, which is achieved through the photocatalytic oxidation of the As(III) and simultaneous adsorbed the generated arsenate [As(V)]. The abilities of As(III) oxidation and removal efficiency for N-CQDs3/MIL-53(Fe) are over 6 times higher than that of pure MIL-53(Fe). The impressively capability of N-CQDs3/MIL-53(Fe) in photocatalytic oxidation and adsorption is attributed to the accelerated separation of photogenerated electron-hole by the in situ embedded N-CQDs. Moreover, the results of the experimental analysis and density functional theory (DFT) DFT calculations confirm that the edge structure of C/O site significantly improves the removal ability of As(III) by forming bidentate C-O-As bonds and occupying coordinatively unsaturated atoms. Therefore, based on the excellent performance and reusability of N-CQDs3/MIL-53(Fe) in As(III) removal, it offers a new potential strategy to develop high efficient MOF based materials for As(III) removal.