Fabrication of Cu2O/ZnTi-LDH p-n heterostructure by grafting Cu2O NPs onto the LDH host layers from Cu-doped ZnTi-LDH and insight into the photocatalytic mechanism

• Published in: Composites. Part B, Engineering Engineering, 2023-02, Vol.250, p.110447, Article 110447
• Main Authors: Xiong, Jie, Zeng, Hong-Yan, Peng, Jin-Feng, Wang, Li-Hui, Peng, Di-Yang, Liu, Fang-Yuan, Xu, Sheng, Yang, Zhuo-Lin
• Format: Article
• Language: English
• Subjects: Cr(VI) reduction; Cu2O/ZnTi layered Double hydroxide; DFT calculation; p-n heterostructure; Tetracycline degradation
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2022.110447

The Cu2O/ZnTi-LDH (Cu2O/LDH) composite was synthesized via Cu-doping into the ZnTi-LDH followed by in-situ reduction strategy for Cr(VI) reduction and tetracycline (TC) degradation under visible-light, where the Cu2O nanoparticles (NPs) were homogeneously embedded onto the LDH host layers through in-situ reducing the Cu-doped ZnTi-LDH (CuZnTi-LDH). The optical, photoelectric and photocatalytic performances of the Cu2O/LDH could be adjusted by changing the Cu-doping amount in the CuZnTi-LDH. As expected, the optimal Cu2O/LDH0.10 exhibited high photocatalytic activities for the Cr(VI) reduction (95.5% Cr(VI) removal) and TC degradation (71.6% TC removal) after 120 min. Based on the experimental and density functional theory (DFT) calculation results, a possible p-n heterostructure formation between Cu2O and ZnTi-LDH as well as the transfer route of photogenerated electron-hole pairs toward for Cr(VI) reduction and TC degradation were proposed. This work may provide a rational and facile strategy for improving the LDH-based materials in catalytic oxidation-reduction reactions. The schematic diagram of the evolution process of the Cu2O/ZnTi-LDH, and photocatalytic of Cr(VI) reduction and TC degradation under visible-light. [Display omitted] •Cu2O NPs were evenly embedded onto the LDH host layers by in-situ reduction strategy.•Cu2O self-photooxidation was restrained due to the high dispersion of Cu2O NPs.•The p-n heterostructure provided a new path for transfer and separation of electron-hole pairs.•Cu2O/ZnTi-LDH displayed excellent Cr(VI) reduction and TC degradation performances.