Department of Chemistry, College of Science, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Department of Chemistry, College of Science, Zhejiang Sci-Tech University, Hangzhou 310018, China; School of Materials Science and Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001, China.
J Colloid Interface Sci. 2019 Apr 1;541:300-311. doi: 10.1016/j.jcis.2019.01.108. Epub 2019 Jan 25.
The ultrathin BiVO nanoflakes decorated with Pd and AuPd nanoparticles (NPs) were respectively synthesized and optimized for the enhanced photocatalysis towards selective oxidation of aromatic alcohols. The monometallic Pd(x)-BiVO samples presented hump-like variation in the photocatalytic activity with increasing Pd amount (x) from 0 to 2.0 wt%. Subsequently, coupling Au with Pd on BiVO nanoflakes resulted in a further improvement in the photocatalysis, with retaining the high selectivity (>99%) for aldehyde production. By tuning metal loading, the typical Au(0.5)Pd(0.5)-BiVO photocatalyst exhibited the highest benzaldehyde yield of 887.7 μmol·g·h, which was 6.0 times that of bare BiVO nanoflakes and 1.35 times that of Pd(1.0)-BiVO photocatalyst. A series of characterizations and DFT calculations confirmed the enhanced light harvesting and charge separation of the Au(0.5)Pd(0.5)-BiVO material, owing to the strong electronic couplings in AuPd NPs and its remarkable influence on the band structure of BiVO. The photocatalytic mechanism studies indicated that the selective oxidation of aromatic alcohols was achieved by the cooperation of photogenerated holes and O radical, and this process was promoted by the interfacial synergism between AuPd NPs and BiVO nanoflakes. This work demonstrates a systematic study on optimizing photocatalysts to improve their performance in light-driven organic transformations as well as highlights the synergistic effect of metal-metal coupling and metal-semiconductor interface on photocatalysis.
超薄 BiVO 纳米片上分别负载了 Pd 和 AuPd 纳米颗粒（NPs），以提高芳香醇选择性氧化的光催化性能。单金属 Pd(x)-BiVO 样品的光催化活性随 Pd 负载量（x）从 0 增加到 2.0wt%时呈现出驼峰式变化。随后，将 Au 与 BiVO 纳米片上的 Pd 耦合进一步提高了光催化性能，同时保持了对醛产物的高选择性（>99%）。通过调节金属负载量，典型的 Au(0.5)Pd(0.5)-BiVO 光催化剂表现出最高的苯甲醛产率为 887.7µmol·g·h，是 bare BiVO 纳米片的 6.0 倍，是 Pd(1.0)-BiVO 光催化剂的 1.35 倍。一系列的表征和 DFT 计算证实了 Au(0.5)Pd(0.5)-BiVO 材料增强的光捕获和电荷分离能力，这归因于 AuPd NPs 中的强电子耦合及其对 BiVO 能带结构的显著影响。光催化机制研究表明，芳香醇的选择性氧化是通过光生空穴和 O 自由基的协同作用实现的，而这个过程则得益于 AuPd NPs 和 BiVO 纳米片之间的界面协同作用。这项工作系统地研究了优化光催化剂以提高其在光驱动有机转化中的性能，并强调了金属-金属耦合和金属-半导体界面在光催化中的协同效应。
