In this study, the electronic and photocatalytic properties of core-shell heterojunctions photocatalysts with reversible configuration of TiO₂ and Bi₂O₃ layers were studied. The core-shell nanostructure, obtained by efficient control of the sol-gel polymerization and impregnation method of variable precursors of semiconductors, makes it possible to study selectively the role of the interfacial charge transfer in each configuration. The morphological, optical, and chemical composition of the core-shell nanostructures were characterized by high-resolution transmission electron microscopy, UV-visible spectroscopy and X-ray photoelectron spectroscopy. The results show the formation of homogenous TiO₂ anatase and Bi₂O₃ layers with a thickness of around 10 and 8 nm, respectively. The interfacial charge carrier dynamic was tracked using time resolved microwave conductivity and transition photocurrent density. The charge transfer, their density, and lifetime were found to rely on the layout layers in the core-shell nanostructure. In optimal core-shell design, Bi₂O₃ collects holes from TiO₂, leaving electrons free to react and increase by 5 times the photocatalytic efficiency toward H₂ generation. This study provides new insight into the importance of the design and elaboration of optimal heterojunction based on the photocatalyst system to improve the photocatalytic activity.

在这项研究中，研究了具有可逆配置的 TiO ₂和 Bi ₂ O ₃层的核壳异质结光催化剂的电子和光催化性能。通过有效控制溶胶-凝胶聚合和半导体可变前体的浸渍方法获得的核-壳纳米结构使得有选择地研究界面电荷转移在每种配置中的作用成为可能。核壳纳米结构的形态、光学和化学成分通过高分辨率透射电子显微镜、紫外-可见光谱和 X 射线光电子能谱进行表征。结果表明形成均质的TiO ₂锐钛矿和Bi ₂O ₃层的厚度分别约为 10 和 8 nm。使用时间分辨微波电导率和跃迁光电流密度跟踪界面电荷载流子动力学。发现电荷转移、它们的密度和寿命依赖于核壳纳米结构中的布局层。在优化的核壳设计中，Bi ₂ O ₃从 TiO ₂收集空穴，使电子自由反应并使光催化效率提高 5 倍以产生H ₂。这项研究为基于光催化剂体系设计和精心设计最佳异质结以提高光催化活性的重要性提供了新的见解。