Identifying the Role of the Local Charge Density on the Hydrogen Evolution Reaction of the Photoelectrode.
Identifying the Role of the Local Charge Density on the Hydrogen Evolution Reaction of the Photoelectrode.
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DOI：
10.1021/acs.jpclett.1c03127
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
W. Nie;Xun Wang;Ziyuan Wang;Yuying Gao;Ruotian Chen;Yong Liu;Can Li;Fengtao Fan
中科院分区：
文献类型：
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作者：
W. Nie;Xun Wang;Ziyuan Wang;Yuying Gao;Ruotian Chen;Yong Liu;Can Li;Fengtao Fan
了解表面电荷在催化反应中的作用对光电化学（PEC）的基础科学具有重要意义。然而，电极/电解质界面上电荷转移位点和催化位点的空间异质性模糊了表面反应过程。本文利用空间分辨光电压显微镜在p-Si光电极上的Pt/Ti阵列上量化了析氢反应（HER）的局部催化电流与表面电荷密度之间的关系。我们发现p-Si表面的Pt/Ti岛是主要的电荷收集区，但也是驱动PEC析氢的唯一催化位点。基于对单个Pt/Ti岛上的局部光电流和光电压的识别成果，我们发现通过同时调节偏置电位和Pt/Ti岛的间距，局部HER电流可以被反应位点的电荷密度线性调节。这些结果强调了表面电荷密度对光电化学催化活性的重要影响。
Understanding the role of surface charges in the catalytic reaction is of great importance to fundamental science in photoelectrochemistry (PEC). However, spatial heterogeneities of charge transfer sites and catalytic sites at the electrode/electrolyte interface obscures the surface reaction process. Herein, we quantified the relationship between the local catalytic current of the hydrogen evolution reaction (HER) and the surface charge density using operando spatially resolved photovoltage microscopy on the Pt/Ti array on the p-Si photoelectrode. We found that the Pt/Ti islands on the p-Si surface worked as the main charge collect areas but as the sole catalytic sites to drive the PEC hydrogen evolution. Based on the achievements of identifying the local photocurrent and photovoltage on a single Pt/Ti island, we found that the local HER current can be linearly regulated by the charge density at reactive sites by concurrently adjusting the bias potential and the spacings of the Pt/Ti islands. These results emphasize the significant impact of the surface charge density on the catalytic activity in photoelectrochemistry.