Titanium dioxide (TiO₂) deposited by atomic layer deposition (ALD) has been the most commonly used protection layer to enhance chemical and photoelectrochemical stabilities of photoelectrodes. In this study, we report a new electrochemical deposition method that can place a thin, conformal TiO₂ coating layer on a photoelectrode. This method takes <1 min and may serve as a practical alternative to ALD for the deposition of a TiO₂ layer. The uniform quality of the TiO₂ protection layer was confirmed by demonstrating the chemical stability of the BiVO₄/TiO₂ electrode in strongly basic media (pH 12 and 13) where BiVO₄ readily dissolves. More importantly, the high-quality TiO₂ protection layer made it possible to comparatively investigate photoelectrochemical properties and stabilities of the BiVO₄ and BiVO₄/TiO₂ electrodes, which was critical to elucidate the effect that the chemical instability of BiVO₄ in basic media has on the rate of photocorrosion. Systematic photoelectrochemical studies for sulfite oxidation and water oxidation provided a coherent understanding of how the interplay among the relative rates of interfacial charge transfer, surface recombination, and photocorrosion affects the photocurrent generation and photostability of BiVO₄. On the basis of this understanding, stable photocurrent generation for water oxidation could be achieved at pH 12 over 20 h using a BiVO₄/TiO₂/FeOOH/NiOOH electrode where FeOOH/NiOOH served as oxygen evolution catalyst. The results and discussion contained in this study provide new insights into the understanding of photocurrent decay caused by photocorrosion involving dissolution, enabling the development of effective strategies to achieve stable photocurrent generation.

中文翻译：

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在碱性介质中通过BiVO ₄光电阳极实现太阳能氧化

通过原子层沉积（ALD）沉积的二氧化钛（TiO ₂）是最常用的保护层，用于增强光电极的化学和光电化学稳定性。在这项研究中，我们报告了一种新的电化学沉积方法，该方法可以在光电极上放置一层薄的，保形的TiO ₂涂层。此方法耗时少于1分钟，可以作为ALD的实用替代方法来沉积TiO ₂层。的TiO 2的质量均匀₂保护层，通过展示BiVO的化学稳定性确认₄ /二氧化钛₂电极在强碱性介质（pH为12和13）其中，BiVO ₄容易溶解。更重要的是，高质量的TiO ₂保护层使得可以比较研究BiVO ₄和BiVO ₄ / TiO ₂电极的光电化学性质和稳定性，这对于阐明BiVO ₄在基本介质中的化学不稳定性的影响至关重要。具有对光腐蚀的速率。对亚硫酸盐氧化和水氧化的系统光电化学研究提供了对界面电荷转移，表面重组和光腐蚀的相对速率之间的相互作用如何影响BiVO ₄的光电流产生和光稳定性的连贯理解。。基于该理解，使用BiVO ₄ / TiO ₂ / FeOOH / NiOOH电极（其中FeOOH / NiOOH用作析氧催化剂），在pH 12下在20 h内可实现稳定的水氧化光电流产生。这项研究中包含的结果和讨论为理解由涉及溶解的光腐蚀引起的光电流衰减提供了新的见解，从而使开发有效的策略来实现稳定的光电流产生成为可能。