Photoelectrochemical (PEC) water splitting has witnessed rapid development because of the potential of converting solar energy into renewable fuels. Photoelectrodes and electrolytes are two basic components for a PEC system. Metal‐oxide photoanodes have been the most popular electrode candidates because of their excellent performance, good stability, abundance, and cost‐effective features. However, metal‐oxide photoanodes suffer from serious charge recombination due to the intrinsically poor electrochemical properties. Therefore, intensive research effort has been devoted to solving these challenges. A variety of effective strategies have been developed, including the construction of nanostructures, introduction of dopants, control of crystal facets, design of junctions, and modification of interfaces. Moreover, it is demonstrated that the combination of multiple strategies is much more efficient than a single one to suppress charge recombination. Herein, the recent advances in metal‐oxide photoanodes for PEC water oxidation are summarized, mainly focusing on the engineering of charge separation and transportation process. At the end of this Review, some perspectives and outlooks for the development and design of metal‐oxide photoanodes are also proposed, hoping to shed light on the rapid growth of this area in the future.

中文翻译：

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金属氧化物光阳极的最新进展：电荷分离和向高效太阳能水分解输送的工程

由于将太阳能转化为可再生燃料的潜力，光电化学（PEC）水分解技术发展迅速。光电电极和电解质是PEC系统的两个基本组件。金属氧化物光阳极由于其优异的性能，良好的稳定性，丰度和经济高效的特性而成为最受欢迎的电极。但是，由于本质上较差的电化学性能，金属氧化物光阳极会发生严重的电荷复合。因此，致力于解决这些挑战的深入研究。已经开发出各种有效的策略，包括纳米结构的构造，掺杂剂的引入，晶体面的控制，结的设计以及界面的修饰。此外，已经证明，多种策略的组合比单个策略抑制电荷重组的效率要高得多。在此，总结了用于PEC水氧化的金属氧化物光阳极的最新进展，主要集中在电荷分离和传输过程的工程上。在本综述的最后，还提出了有关金属氧化物光阳极开发和设计的一些观点和展望，以期阐明该领域的快速增长。