He Jing, Chen Shiyuan, Ma Zhuang, Wang Miao, He Qinggang
College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, Hangzhou, Zhejiang 310027, China.
Zhejiang Province key Laboratory of Quantum Technology and Device, Department of Physics, Zhejiang University, Hangzhou 310027, China.
ACS Nano. 2024 Sep 3;18(35):24283-24294. doi: 10.1021/acsnano.4c06049. Epub 2024 Aug 20.
To elucidate the microstructure and charge transfer behavior at the interface of Pd/metal oxide semiconductor (MOS) catalysts and systematically explore the crucial role of the Mott-Schottky effect in the oxygen reduction reaction (ORR) electrocatalysis process, this study established a testing system for spatially identifying Mott-Schottky effects and electronic properties at Pd/MOS interfaces, leveraging highly sensitive Kelvin probe force microscopy (KPFM). This system enabled visualization and quantification of the surface potential difference and Mott-Schottky barrier height (Φ) at the Pd/MOS heterojunction interfaces. Furthermore, a series of Pd/MOS Mott-Schottky catalysts were constructed based on differences in work functions between Pd and n-type MOS. The abundant oxygen vacancies in these catalysts facilitated the adsorption and activation of oxygen molecules. Notably, the intensity of the built-in electric field in the Pd/MOS Mott-Schottky catalysts was calculated through surface potential and zeta potential analysis, systematically correlating the Mott-Schottky effect at the heterojunction interface of Pd/MOS with ORR activity and kinetics. By comprehensively exploring the correlation between the Mott-Schottky effect and ORR performance in Pd/MOS catalysts using the KPFM testing system, this study provides necessary tools and approaches for a deep understanding of heterogeneous interface charge transfer mechanisms, as well as for optimizing catalyst design and enhancing ORR performance.
为了阐明钯/金属氧化物半导体（MOS）催化剂界面的微观结构和电荷转移行为，并系统地探究莫特-肖特基效应在氧还原反应（ORR）电催化过程中的关键作用，本研究利用高灵敏度开尔文探针力显微镜（KPFM）建立了一个用于空间识别钯/MOS界面莫特-肖特基效应和电子性质的测试系统。该系统能够可视化和量化钯/MOS异质结界面处的表面电势差和莫特-肖特基势垒高度（Φ）。此外，基于钯与n型MOS功函数的差异构建了一系列钯/MOS莫特-肖特基催化剂。这些催化剂中丰富的氧空位促进了氧分子的吸附和活化。值得注意的是，通过表面电势和zeta电势分析计算了钯/MOS莫特-肖特基催化剂中内建电场的强度，系统地将钯/MOS异质结界面处的莫特-肖特基效应与ORR活性和动力学相关联。通过使用KPFM测试系统全面探究钯/MOS催化剂中莫特-肖特基效应与ORR性能之间的相关性，本研究为深入理解异质界面电荷转移机制以及优化催化剂设计和提高ORR性能提供了必要的工具和方法。
