Abstract In recent days, manganese oxide nanoparticles (MnO 2 NPs) have intrigued material science researches extensively due to its wide range of applications. They are widely used in energy storage devices (lithium-ion batteries, capacitors), catalysts, adsorbent, sensors and imaging, therapeutic activity, etc. Since they hold a lot of distinguished potentials, a robust protocol for cheap, stable, biocompatible and eco-friendly MnO 2 NPs is necessary. They can be categorized into different phases like α, β, δ and others. Thus, owing to their peculiar character, they could be utilized for various purposes depending on the mode of action and applications. Hence, this review has summarized conventional methods, such as hydrothermal, sol–gel, oxidation–reduction used for the generation of MnO 2 NPs. Likewise, morphological characterization by various spectroscopic techniques also outlined. It is found that the particular method of generation of MnO 2 NPs is useful for a specific phase. Graphic Abstract Graphical representation of manganese dioxide nanoparticles: synthesis and application

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二氧化锰纳米粒子：合成、应用和挑战

摘要 近年来，氧化锰纳米粒子 (MnO 2 NPs) 由于其广泛的应用而引起了材料科学研究的广泛关注。它们广泛用于能量存储设备（锂离子电池、电容器）、催化剂、吸附剂、传感器和成像、治疗活性等。 由于它们具有许多显着的潜力，因此是廉价、稳定、生物相容和生态的强大协议-友好的MnO 2 NPs是必要的。它们可以分为不同的阶段，如 α、β、δ 等。因此，由于它们的特殊特性，它们可以根据作用方式和应用用于各种目的。因此，本综述总结了用于生成 MnO 2 NPs 的传统方法，例如水热法、溶胶-凝胶法、氧化还原法。同样地，还概述了通过各种光谱技术进行的形态学表征。发现生成MnO 2 NPs的特定方法对于特定相是有用的。图形摘要 二氧化锰纳米粒子的图形表示：合成和应用