Shi Jianhui, Pu Kaikai, Zhao Ting, Shi Jiating, Zheng Na, Nie Lijun, Xue Kunkun, Gao Yuhang
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030600, China.
College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030600, China.
J Environ Sci (China). 2025 Jun;152:637-653. doi: 10.1016/j.jes.2024.05.034. Epub 2024 May 31.
NH-MIL-125 and its derivatives are receiving more attention in various aspects of photocatalytic reactions, especially in the photocatalytic hydrogen peroxide (HO) production from water (HO) and oxygen (O), which is a promising and sustainable strategy. However, the generation of HO from NH-MIL-125 is far from satisfactory due to rapid photo-generated carriers recombination and poor surface electron transfer. In the work, the composite photocatalyst CQDs/TiO/NH-MIL-125 (C/T/NM) was designed for the first time by one-step hydrothermal method. TiO was in situ converted from partial NH-MIL-125 (NM) during the successful loaded of Carbon quantum dots (CQDs) by hydrothermal process. The results indicated the type Ⅱ heterojunction was successfully constructed between the NM and TiO interface, which could promote the transmission of photo-generated electrons. In addition, the successful loaded of CQDs could effectively transfer and stored the photo-generated electrons to the photocatalyst surface to participate in the reaction, and further avoiding the recombination of photo-generated carriers. The C/T/NM composite photocatalyst achieved a HO generation of 455 µmol/L for 5 hours under visible light without oxygen bubbling, which was 7.1 times superior to that of NM. The HO generation rate reached 645.4 µM/(g·h), which was in priority in the reported literature under the same conditions. Finally, based on the active species capture experiments, energy band structure analysis and the photoelectrochemical measurements, a possible mechanism for the efficient HO generation through C/T/NM had been proposed. This work provided new ideas for designing NH-MIL-125 based composite photocatalysts for the production of HO.
NH-MIL-125及其衍生物在光催化反应的各个方面正受到越来越多的关注，特别是在由水（H₂O）和氧气（O₂）光催化生产过氧化氢（H₂O₂）方面，这是一种有前景的可持续策略。然而，由于光生载流子快速复合以及表面电子转移较差，NH-MIL-125产生H₂O₂的效率远不尽人意。在这项工作中，首次通过一步水热法设计了复合光催化剂CQDs/TiO₂/NH-MIL-125（C/T/NM）。在通过水热过程成功负载碳量子点（CQDs）期间，TiO₂由部分NH-MIL-125（NM）原位转化而来。结果表明，在NM和TiO₂界面之间成功构建了Ⅱ型异质结，这可以促进光生电子的传输。此外，CQDs的成功负载可以有效地将光生电子转移并存储到光催化剂表面以参与反应，进而避免光生载流子的复合。C/T/NM复合光催化剂在可见光下无氧鼓泡的条件下5小时内实现了455 μmol/L的H₂O₂生成量，这比NM高出7.1倍。H₂O₂生成速率达到645.4 μM/(g·h)，在相同条件下在已报道的文献中处于领先地位。最后，基于活性物种捕获实验、能带结构分析和光电化学测量，提出了通过C/T/NM高效生成H₂O₂的可能机制。这项工作为设计用于生产H₂O₂的基于NH-MIL-125的复合光催化剂提供了新思路。
