Photoelectrochemical (PEC) water splitting offers an attractive option for solar fuel production to solve the global energy crisis and environmental issues, but the present low efficiency hinders its practical application. Interface engineering has been demonstrated to be critical for developing high-performance photoelectrodes for efficient water splitting. However, effective interface engineering requires insightful understanding of the interfacial thermodynamics, carrier dynamics, and surface reaction mechanisms, all of which essentially depend on the advances of study techniques. Herein, electrochemical and optical spectroscopic techniques applied for interface studies in PEC systems are overviewed. The fundamentals and data analysis methods of each technique are introduced, in company with representative achievements in understanding the PEC interfaces. Both conventional and newly developed techniques are included, with some discussions on their advantages and limitations. Finally, a perspective on the challenges and the future progress of techniques for PEC interface studies is also given. This review could inspire further technique development and a mechanistic understanding of PEC water splitting.

中文翻译：

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工程化水分解光电极中的界面-技术发展概述

光电化学（PEC）水分解为太阳能燃料生产提供了一个有吸引力的选择，以解决全球能源危机和环境问题，但是目前的低效率阻碍了其实际应用。事实证明，界面工程对于开发用于高效水分解的高性能光电电极至关重要。然而，有效的界面工程需要对界面热力学，载流子动力学和表面反应机理有深刻的了解，所有这些基本上都取决于研究技术的进步。在此，概述了在PEC系统中用于界面研究的电化学和光谱技术。介绍了每种技术的基础知识和数据分析方法，在理解PEC界面方面取得了具有代表性的成就。包括传统技术和新开发的技术，并对其优点和局限性进行了一些讨论。最后，给出了PEC接口研究技术面临的挑战和未来进展的观点。这项审查可能会激发进一步的技术开发和对PEC水分解的机械理解。