Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China.
Engineering Research Center for Water Pollution Source Control & Eco-Remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing, 100083, China.
Environ Sci Pollut Res Int. 2024 Apr;31(20):29101-29112. doi: 10.1007/s11356-024-32827-8. Epub 2024 Apr 3.
The transformation of photogenerated charge carriers (PC) in variable dimensional photocatalyst plays a pivotal role in unraveling the generation of reactive species (RS). However, the dimensional structure-activity relationship in photocatalysis remains elusive, with limited insights into its intricacies. Herein, we report a controlled synthesis strategy by using polyvinyl pyrrolidone (PVP)-assisted precipitation method for BiOI photocatalyst. Due to the steric hindrance of PVP, the 3D microsphere (3D-PVP0.5) and porous structure (3D-PVP1) of BiOI catalysts have been successfully prepared at room temperature. The 3D-PVP1 photocatalyst contains abundant mesopores and larger pores, which significantly shorten the diffusion distance of PC. Also, these PC in porous structure is beneficial for transferring from the inner phase to the surface of materials. Combined with optical property and radicals trapping experiments, the recombination rate of PC in porous structure performs a significant decrease, leading to the generation of more dominated ROS (•O and h). The •O played a dominated role (86.98% of contribution rate) in photodegradation of tetracycline (TC) in 3D-PVP1 photocatalytic process. Compared with 2D nanosheet of BiOI (16.7% removal rate of TC), the as-prepared 3D porous structure of BiOI catalyst exhibits unique stable and high removal capacities (90.5%) for TC photodegradation under visible light irradiation. The k of 3D-PVP1 photocatalyst increased by 5.1 times than that of 2D nanosheet. To investigate its practical application, the effects of inorganic anions and pH have been systematically studied. This work sheds light on the design of variable dimension BiOI catalyst and provides more insight into the transfer mechanism of PC.
光生载流子（PC）在变维光催化剂中的转化在揭示活性物质（RS）的产生方面起着关键作用。然而，光催化中的维度结构-活性关系仍然难以捉摸，对其复杂性的了解有限。在此，我们报告了一种使用聚乙烯吡咯烷酮（PVP）辅助沉淀法制备 BiOI 光催化剂的控制合成策略。由于 PVP 的空间位阻，BiOI 催化剂的 3D 微球（3D-PVP0.5）和多孔结构（3D-PVP1）已在室温下成功制备。3D-PVP1 光催化剂含有丰富的介孔和较大的孔，可显著缩短 PC 的扩散距离。此外，多孔结构中的这些 PC 有利于从内相转移到材料表面。结合光学性质和自由基捕获实验，多孔结构中 PC 的复合率显著降低，导致更多主导性 ROS（•O 和 h）的产生。•O 在 3D-PVP1 光催化过程中对四环素（TC）的光降解起主导作用（贡献率为 86.98%）。与 2D 纳米片 BiOI（TC 的去除率为 16.7%）相比，所制备的 3D 多孔结构 BiOI 催化剂在可见光照射下对 TC 光降解表现出独特的稳定和高去除能力（90.5%）。3D-PVP1 光催化剂的 k 值比 2D 纳米片高 5.1 倍。为了研究其实际应用，系统研究了无机阴离子和 pH 的影响。这项工作为变维 BiOI 催化剂的设计提供了启示，并深入了解了 PC 的转移机制。
