Photoelectrochemical Imaging of Charge Separation between MoS 2 Triangles and Insulating SiO 2 Support

作者：Ziyuan Wang, Qing Huang, Chenwei Ni, Tianyu Bo, Fengtao Fan, Michael V. Mirkin · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c02136 · 被引用次数：14 · 研究领域：Electrocatalysts for Energy Conversion、Electrochemical Analysis and Applications、Transition Metal Oxide Nanomaterials

High Resolution Image Download MS PowerPoint Slide The role of the insulating support in photocatalysis is poorly understood. Using high-resolution photo-scanning electrochemical microscopy (photo-SECM), we observed significant spatial charge separation in few-layer-thick molybdenum disulfide (MoS 2 ) triangles attached to a SiO 2 substrate. Spatially resolved surface photovoltage (SPV) measurements revealed that photogenerated holes migrate from MoS 2 to the SiO 2 surface and travel laterally over distances exceeding 2 μm, driven by the built-in electric field of ∼1.7 kV/cm. In thicker and less uniform flakes, the charge separation is dominated by internal driving forces within MoS 2, without significant contribution from SiO 2 . These findings underscore the importance of insulator–semiconductor interactions for effective charge separation, suggesting a new strategy for optimizing photocatalytic systems.