Bubble evolution from photo(electro)catalytic water splitting plays a vital role in the interfacial mass transport on photocatalyst surface. However, little success has been achieved to optimize this process, restricted by the poor understanding. Herein, taking photoelectrochemical (PEC) water splitting over a titanium dioxide (TiO₂) nanorod-array electrode as a model system, experiments were performed to study single oxygen bubble dynamics by combining electrochemical measurement and high-speed microscopic imaging. The experimental results indicate that the departure of bubble from photoelectrode is retarded by light irradiation, but the traditional bubble departure criterions fail to predict the bubble departure diameters especially in high light intensity. Additional analysis reveals that the light irradiation causes the Marangoni force acting on the evolving bubble, because it induces temperature rise and generates dissolved gas. A modified force balance model for bubble departure from photoelectrode was developed by adding Marangoni force. This modified model that takes account of the light-induced temperature rise and the dissolved gas, agrees well with the experimental data and can be extended to other photo(electro)catalytic reactions.

光（电）催化水分解产生的气泡在光催化剂表面的界面传质中起着至关重要的作用。但是，由于缺乏了解，在优化此过程方面几乎没有取得成功。在此，将光化学（PEC）水分解成二氧化钛（TiO ₂）纳米棒阵列电极作为模型系统，通过结合电化学测量和高速显微镜成像进行了研究单个氧气泡动力学的实验。实验结果表明，光辐照可抑制气泡从光电极的离开，但是传统的气泡离开标准无法预测气泡的离开直径，特别是在高光强度下。进一步的分析表明，光辐照会引起马兰哥尼力作用在不断演化的气泡上，因为它会引起温度升高并产生溶解气体。通过添加Marangoni力，开发了一种改进的气泡脱离光电极的力平衡模型。此修改后的模型考虑了光引起的温度升高和溶解气体的影响，