As an emerging and important family of two-dimensional (2D) nanomaterials, MXene has demonstrated to be a type of promising electrode materials for energy storage devices. Hazardous fluorine-containing acids are commonly applied in exfoliation synthesis of MXenes, which bring about additional safety and environmental concerns. Herein, we proposed a novel and effective UV-induced selective etching method to fabricate fluorine-free mesoporous Mo2C MXene from Mo2Ga2C bulk ceramic in several hours. The resultant MXene exhibits a distinct 2D sheet-like structure without much contamination of impurity ions. When the as-synthesized Mo2C MXene is explored as potential anode materials for rechargeable batteries, excellent rate capability and cycling stability are achieved for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Furthermore, the assembled flexible Mo2C MXene-based batteries manifested excellent capacity retentions under bending states. Therefore, this Mo2C MXene has great potential for practical energy storage applications. This innovative approach can be further developed for fabricating other MXenes from UV-sensitive precursors.

中文翻译：

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二维无氟介孔 Mo2C MXene 通过紫外线诱导的 Mo2Ga2C 选择性蚀刻用于储能

作为一种新兴且重要的二维 (2D) 纳米材料家族，MXene 已被证明是一种很有前途的储能设备电极材料。危险的含氟酸通常用于 MXenes 的剥离合成，这带来了额外的安全和环境问题。在此，我们提出了一种新颖有效的紫外线诱导选择性蚀刻方法，可在数小时内从 Mo2Ga2C 块状陶瓷制备无氟介孔 Mo2C MXene。由此产生的 MXene 表现出独特的 2D 片状结构，而没有太多杂质离子污染。当合成的 Mo2C MXene 被探索作为可充电电池的潜在负极材料时，锂离子电池 (LIB) 和钠离子电池 (SIB) 均实现了优异的倍率性能和循环稳定性。此外，组装的柔性 Mo2C MXene 基电池在弯曲状态下表现出优异的容量保持率。因此，这种 Mo2C MXene 在实际储能应用中具有巨大的潜力。这种创新方法可以进一步开发用于从紫外线敏感前体制造其他 MXene。