Department of Physics, City University of Hong Kong, 999077, Hong Kong Special Administrative Region.
Department of Material and Science Engineering, City University of Hong Kong, 999077, Hong Kong Special Administrative Region.
J Colloid Interface Sci. 2023 Sep 15;646:687-694. doi: 10.1016/j.jcis.2023.05.097. Epub 2023 May 19.
The photoelectrochemical (PEC) performance of bismuth vanadate (BiVO) suffers from sluggish charge mobility and substantial charge recombination losses due to its intrinsic defect. To rectify the problem, we developed a novel approach to prepare an n-n type II BVO-BVO homojunction with staggered band alignment. This architecture involves a built-in electric field that facilitating the electron-hole separation at the BVO/BVO interface. As a result, the BVO-BVO homojunction shows superior photocurrent density up to 3.6 mA/cm at 1.23 V vs. reversible hydrogen electrode (RHE) with 0.1 M sodium sulfite as the hole scavenger, which is 3 times higher than that of the single-layer BiVO photoanode. Unlike the previous efforts that modifying the PEC performance of BiVO photoanodes through incorporating heteroatoms, the highly-efficient BVO-BVO homojunction was achieved without incorporating any heteroatoms in this work. The remarkable PEC activity of the BVO-BVO homojunction highlights the tremendous importance of reducing the charge recombination rate at the interface by constructing the homojunction and offers an effective strategy to form the heteroatoms-free BiVO thin film as an efficient photoanode material for practical PEC applications.
由于本征缺陷，钒酸铋（BiVO）的光电化学（PEC）性能受到缓慢的电荷迁移率和大量电荷复合损失的影响。为了解决这个问题，我们开发了一种制备具有交错能带排列的 n-n 型 II 型 BVO-BVO 同质结的新方法。这种结构涉及内置电场，有利于 BVO/BVO 界面处的电子-空穴分离。结果，BVO-BVO 同质结在 0.1 M 亚硫酸钠作为空穴捕获剂时，在 1.23 V vs. 可逆氢电极（RHE）下表现出高达 3.6 mA/cm 的光电流密度，是单层 BiVO 光阳极的 3 倍。与以前通过掺入杂原子来修饰 BiVO 光阳极的 PEC 性能的努力不同，在这项工作中，没有掺入任何杂原子就实现了高效的 BVO-BVO 同质结。BVO-BVO 同质结的显著 PEC 活性突出了通过构建同质结降低界面电荷复合率的重要性，并为形成无杂原子的 BiVO 薄膜作为用于实际 PEC 应用的高效光阳极材料提供了一种有效策略。
