Direct Z-scheme 0D/2D heterojunction of CuO quantum Dots/ultrathin CoAl-LDH for boosting charge separation and photocatalytic CO2 reduction. (1st January 2022)

• Record Type: Journal Article
• Authors: Jiang, Yue; Guo, Jiaqing; Li, Xiaoli; Wu, Guang; Mu, Manman; Yin, Xiaohong
• Is Part Of: Solar energy. Volume 231(2022)
• Page Start: 705
• Page End: 715
• Publication Date: 2022-01-01
• Subjects: Ultrathin CoAl-LDH -- 0D/2D heterojunction hybrid -- Direct Z-scheme -- CO2 photoreduction; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2021.12.001
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Ultrathin CoAl-LDH (CoAl-u) with abundant oxygen defects was successfully prepared. A direct Z-scheme 0D/2D heterojunction of CuO QDs/CoAl-u hybrid was first fabricated. The composite displays an excellent photocatalytic CO2 reduction to CH3 OH at 4.5 wt% CuO QDs loading. A possible photocatalytic mechanism of the Z-scheme heterojunction was elucidated by characterization technologies and DFT calculation. Abstract: A direct Z-scheme 0D/2D heterojunction of CuO Quantum dots/ultrathin CoAl-LDH (CuO/CoAl-u) was fabricated by a simple electrostatic self-assembly process for photocatalytic CO2 reduction. An intimate interaction is formed between CuO and CoAl-u, which enables an effective Z-scheme interfacial charge transfer and thus boosts the charge separation as evidenced by various characterization technologies. Notably, the 4.5 %CuO/CoAl-u heterojunction achieves superior photocatalytic performance with a CH3 OH yield of 283.26 μmol·g −1 ·h −1, which is higher than the pristine CoAl-u. Such the enhanced photocatalytic performance turns out to originate from prominent optical absorption property, effective separation of photo-induced carriers in CuO/CoAl-u and preserved higher reduction ability of CoAl-u. XPS measurements together with density functional theory calculations provide a clear description of the charge separation pathways and thus a possible mechanism for photocatalytic CO2 reduction is proposed. This work would provide a novel opportunity for the development of LDH-based photocatalysts with the enhanced activities in solar energy conversion.