WPI Center for Materials Nanoarchitectonics (MANA), National Institute For Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044, Japan.
J Am Chem Soc. 2010 Oct 20;132(41):14415-7. doi: 10.1021/ja107589m.
Although artificial capsule structures have been thoroughly investigated, functionality at the surfaces of their interiors has been surprisingly overlooked. In order to exploit this aspect of capsular structure, we here report the breakthrough fabrication of metallic (platinum) microcapsules with sufficient accessibility and electroactivity at both interior and exterior surfaces (open-mouthed platinum microcapsules), and also we demonstrate improvements in electrochemical and catalytic functions to emphasize the practical importance of our concept. The open-mouthed platinum microcapsules were prepared by template synthesis using polystyrene spheres, where surface-fused crystalline nanoparticles formed a capsule shell. Subsequent removal of the polystyrene spheres induced formation of mouth-like openings. The open-mouthed platinum microcapsules exhibit a substantial increase of their electrode capability for methanol oxidation and catalytic activities for carbon monoxide (CO) oxidation. Notably, activity loss during CO oxidation due to undesirable particle agglomeration can be drastically suppressed using the open-mouthed microcapsules.
虽然人工胶囊结构已经得到了深入的研究，但它们内部表面的功能却出人意料地被忽视了。为了利用胶囊结构的这一方面，我们在这里报道了突破性的制备方法，制备了具有足够内外表面可及性和电化学活性的金属（铂）微胶囊（开口铂微胶囊），并展示了电化学和催化功能的改进，以强调我们概念的实际重要性。开口铂微胶囊通过使用聚苯乙烯球的模板合成制备，其中表面融合的结晶纳米颗粒形成了胶囊壳。随后去除聚苯乙烯球诱导了口状开口的形成。开口铂微胶囊表现出对甲醇氧化的电极能力以及对一氧化碳（CO）氧化的催化活性的显著增加。值得注意的是，使用开口微胶囊可以大大抑制 CO 氧化过程中由于颗粒团聚而导致的活性损失。
