State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan 430070 , P. R. China.
Department of Physics, Faculty of Science , King Abdulaziz University , Jeddah 21589 , Saudi Arabia.
ACS Appl Mater Interfaces. 2019 Feb 13;11(6):5581-5589. doi: 10.1021/acsami.8b02552. Epub 2018 May 2.
Photocatalytic CO conversion into solar fuels has an alluring prospect. However, the rapid recombination of photogenerated electron-hole pairs for TiO-based photocatalyst hinders its wide application. To alleviate this bottleneck, a ternary hybrid TiO-MnO -Pt composite is excogitated. Taking advantage of the surface junction between {001} and {101} facets, MnO nanosheets and Pt nanoparticles are selectively deposited on each facet by a facile photodeposition method. This design accomplishes the formation of two heterojunctions: p-n junction between MnO and TiO {001} facet and metal-semiconductor junction between Pt and TiO {101} facet. Both of them, together with the surface heterojunction between {001} and {101} facets, are contributive to the spatial separation of the photogenerated electron-hole pairs. Thanks to their cooperative and synergistic effect, the as-prepared composite photocatalyst exhibits a promoted yield of CH and CHOH, which is over threefold of pristine TiO nanosheets films. The conjecture of the mechanism that selective formation of multijunction structure maximizes the separation and transfer efficiency of photogenerated charge carriers is proved by the photoelectrochemical analysis. This work not only successfully achieves an efficient multijunction photocatalyst by ingenious design but also provides insight into the mechanism of the performance enhancement.
光催化 CO 转化为太阳能燃料具有诱人的前景。然而，基于 TiO2 的光催化剂中光生电子-空穴对的快速复合阻碍了其广泛应用。为了缓解这一瓶颈，设计了一种三元复合 TiO-MnO2-Pt 复合材料。利用 {001} 和 {101} 面之间的表面结，通过简便的光沉积方法在每个面上选择性地沉积 MnO2 纳米片和 Pt 纳米颗粒。这种设计实现了两种异质结的形成：MnO2 和 TiO {001} 面之间的 p-n 结和 Pt 和 TiO {101} 面之间的金属半导体结。它们共同作用以及 {001} 和 {101} 面之间的表面异质结有助于光生电子-空穴对的空间分离。由于它们的协同作用，所制备的复合光催化剂表现出 CH 和 CHOH 的产量增加，是原始 TiO2 纳米片薄膜的三倍以上。通过光电化学分析证明了选择性形成多结结构的机制假设，即最大限度地提高光生载流子的分离和转移效率。这项工作不仅通过巧妙的设计成功实现了高效的多结光催化剂，而且还深入了解了性能增强的机制。
