Superoxide ion (O₂^•–) is of great significance as a radical species implicated in diverse chemical and biological systems. However, the chemistry knowledge of O₂^•– is rather scarce. In addition, numerous studies on O₂^•– were conducted within the latter half of the 20th century. Therefore, the current advancement in technology and instrumentation will certainly provide better insights into mechanisms and products of O₂^•– reactions and thus will result in new findings. This review emphasizes the state-of-the-art research on O₂^•– so as to enable researchers to venture into future research. It comprises the main characteristics of O₂^•– followed by generation methods. The reaction types of O₂^•– are reviewed, and its potential applications including the destruction of hazardous chemicals, synthesis of organic compounds, and many other applications are highlighted. The O₂^•– environmental chemistry is also discussed. The detection methods of O₂^•– are categorized and elaborated. Special attention is given to the feasibility of using ionic liquids as media for O₂^•–, addressing the latest progress of generation and applications. The effect of electrodes on the O₂^•– electrochemical generation is reviewed. Finally, some remarks and future perspectives are concluded.

中文翻译：

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超氧化物离子：产生及其化学意义

作为涉及多种化学和生物系统的自由基，超氧离子（O ₂ ^•–）具有重要意义。但是，O ₂ ^•–的化学知识相当匮乏。此外，在20世纪下半叶，对O ₂ ^•进行了大量研究。因此，当前技术和仪器的进步必将为O ₂ ^•反应的机理和产物提供更好的见解，从而带来新的发现。这篇综述着重介绍了关于O ₂ ^•的最新研究，以使研究人员能够冒险进行未来的研究。它包括O ₂的主要特征^•–其次是生成方法。对O ₂ ^•的反应类型进行了综述，并重点介绍了其潜在的应用，包括破坏有害化学物质，合成有机化合物以及许多其他应用。还讨论了O ₂ ^•–环境化学。对O ₂ ^•–的检测方法进行了分类和阐述。特别注意使用离子液体作为O ₂ ^•的介质的可行性，以解决生成和应用的最新进展。综述了电极对O ₂ ^•电化学生成的影响。最后，总结了一些言论和未来展望。